diff --git a/platform/mv3/scriptlets/no-addeventlistener-if.entity.js b/platform/mv3/scriptlets/no-addeventlistener-if.entity.js
index e9f0f2e6e..dac815011 100644
--- a/platform/mv3/scriptlets/no-addeventlistener-if.entity.js
+++ b/platform/mv3/scriptlets/no-addeventlistener-if.entity.js
@@ -56,15 +56,70 @@ const regexpFromArg = arg => {
 
 /******************************************************************************/
 
+// Dependencies
+
+const scriptletGlobals = new Map();
+
+function safeSelf() {
+    if ( scriptletGlobals.has('safeSelf') ) {
+        return scriptletGlobals.get('safeSelf');
+    }
+    const safe = {
+        'RegExp': self.RegExp,
+        'RegExp_test': self.RegExp.prototype.test,
+        'RegExp_exec': self.RegExp.prototype.exec,
+        'addEventListener': self.EventTarget.prototype.addEventListener,
+        'removeEventListener': self.EventTarget.prototype.removeEventListener,
+    };
+    scriptletGlobals.set('safeSelf', safe);
+    return safe;
+}
+
+function runAt(fn, when) {
+    const intFromReadyState = state => {
+        const targets = {
+            'loading': 1,
+            'interactive': 2, 'end': 2, '2': 2,
+            'complete': 3, 'idle': 3, '3': 3,
+        };
+        const tokens = Array.isArray(state) ? state : [ state ];
+        for ( const token of tokens ) {
+            const prop = `${token}`;
+            if ( targets.hasOwnProperty(prop) === false ) { continue; }
+            return targets[prop];
+        }
+        return 0;
+    };
+    const runAt = intFromReadyState(when);
+    if ( intFromReadyState(document.readyState) >= runAt ) {
+        fn(); return;
+    }
+    const onStateChange = ( ) => {
+        if ( intFromReadyState(document.readyState) < runAt ) { return; }
+        fn();
+        safe.removeEventListener.apply(document, args);
+    };
+    const safe = safeSelf();
+    const args = [ 'readystatechange', onStateChange, { capture: true } ];
+    safe.addEventListener.apply(document, args);
+}
+
+/******************************************************************************/
+
 const scriptlet = (
-    needle1 = '',
-    needle2 = ''
+    arg1 = '',
+    arg2 = ''
 ) => {
-    const reNeedle1 = regexpFromArg(needle1);
-    const reNeedle2 = regexpFromArg(needle2);
-    self.EventTarget.prototype.addEventListener = new Proxy(
-        self.EventTarget.prototype.addEventListener,
-        {
+    const details = typeof arg1 !== 'object'
+        ? { type: arg1, pattern: arg2 }
+        : arg1;
+    const { type = '', pattern = '' } = details;
+    if ( typeof type !== 'string' ) { return; }
+    if ( typeof pattern !== 'string' ) { return; }
+    const reType = regexpFromArg(type);
+    const rePattern = regexpFromArg(pattern);
+    const trapEddEventListeners = ( ) => {
+        const eventListenerHandler = {
             apply: function(target, thisArg, args) {
                 let type, handler;
                 try {
@@ -73,14 +128,21 @@ const scriptlet = (
                 } catch(ex) {
                 }
                 if (
-                    reNeedle1.test(type) === false ||
-                    reNeedle2.test(handler) === false
+                    reType.test(type) === false ||
+                    rePattern.test(handler) === false
                 ) {
                     return target.apply(thisArg, args);
                 }
             }
-        }
-    );
+        };
+        self.EventTarget.prototype.addEventListener = new Proxy(
+            self.EventTarget.prototype.addEventListener,
+            eventListenerHandler
+        );
+    };
+    runAt(( ) => {
+        trapEddEventListeners();
+    }, details.runAt);
 };
 
 /******************************************************************************/
diff --git a/platform/mv3/scriptlets/no-addeventlistener-if.js b/platform/mv3/scriptlets/no-addeventlistener-if.js
index e8da01169..7ec69df79 100644
--- a/platform/mv3/scriptlets/no-addeventlistener-if.js
+++ b/platform/mv3/scriptlets/no-addeventlistener-if.js
@@ -57,15 +57,70 @@ const regexpFromArg = arg => {
 
 /******************************************************************************/
 
+// Dependencies
+
+const scriptletGlobals = new Map();
+
+function safeSelf() {
+    if ( scriptletGlobals.has('safeSelf') ) {
+        return scriptletGlobals.get('safeSelf');
+    }
+    const safe = {
+        'RegExp': self.RegExp,
+        'RegExp_test': self.RegExp.prototype.test,
+        'RegExp_exec': self.RegExp.prototype.exec,
+        'addEventListener': self.EventTarget.prototype.addEventListener,
+        'removeEventListener': self.EventTarget.prototype.removeEventListener,
+    };
+    scriptletGlobals.set('safeSelf', safe);
+    return safe;
+}
+
+function runAt(fn, when) {
+    const intFromReadyState = state => {
+        const targets = {
+            'loading': 1,
+            'interactive': 2, 'end': 2, '2': 2,
+            'complete': 3, 'idle': 3, '3': 3,
+        };
+        const tokens = Array.isArray(state) ? state : [ state ];
+        for ( const token of tokens ) {
+            const prop = `${token}`;
+            if ( targets.hasOwnProperty(prop) === false ) { continue; }
+            return targets[prop];
+        }
+        return 0;
+    };
+    const runAt = intFromReadyState(when);
+    if ( intFromReadyState(document.readyState) >= runAt ) {
+        fn(); return;
+    }
+    const onStateChange = ( ) => {
+        if ( intFromReadyState(document.readyState) < runAt ) { return; }
+        fn();
+        safe.removeEventListener.apply(document, args);
+    };
+    const safe = safeSelf();
+    const args = [ 'readystatechange', onStateChange, { capture: true } ];
+    safe.addEventListener.apply(document, args);
+}
+
+/******************************************************************************/
+
 const scriptlet = (
-    needle1 = '',
-    needle2 = ''
+    arg1 = '',
+    arg2 = ''
 ) => {
-    const reNeedle1 = regexpFromArg(needle1);
-    const reNeedle2 = regexpFromArg(needle2);
-    self.EventTarget.prototype.addEventListener = new Proxy(
-        self.EventTarget.prototype.addEventListener,
-        {
+    const details = typeof arg1 !== 'object'
+        ? { type: arg1, pattern: arg2 }
+        : arg1;
+    const { type = '', pattern = '' } = details;
+    if ( typeof type !== 'string' ) { return; }
+    if ( typeof pattern !== 'string' ) { return; }
+    const reType = regexpFromArg(type);
+    const rePattern = regexpFromArg(pattern);
+    const trapEddEventListeners = ( ) => {
+        const eventListenerHandler = {
             apply: function(target, thisArg, args) {
                 let type, handler;
                 try {
@@ -74,14 +129,21 @@ const scriptlet = (
                 } catch(ex) {
                 }
                 if (
-                    reNeedle1.test(type) === false ||
-                    reNeedle2.test(handler) === false
+                    reType.test(type) === false ||
+                    rePattern.test(handler) === false
                 ) {
                     return target.apply(thisArg, args);
                 }
             }
-        }
-    );
+        };
+        self.EventTarget.prototype.addEventListener = new Proxy(
+            self.EventTarget.prototype.addEventListener,
+            eventListenerHandler
+        );
+    };
+    runAt(( ) => {
+        trapEddEventListeners();
+    }, details.runAt);
 };
 
 /******************************************************************************/
diff --git a/platform/mv3/scriptlets/no-setinterval-if.js b/platform/mv3/scriptlets/no-setinterval-if.js
index 5792ecc3f..77f4cab24 100644
--- a/platform/mv3/scriptlets/no-setinterval-if.js
+++ b/platform/mv3/scriptlets/no-setinterval-if.js
@@ -83,7 +83,13 @@ const scriptlet = (
                 args[0] = function(){};
             }
             return target.apply(thisArg, args);
-        }
+        },
+        get(target, prop, receiver) {
+            if ( prop === 'toString' ) {
+                return target.toString.bind(target);
+            }
+            return Reflect.get(target, prop, receiver);
+        },
     });
 };
 
diff --git a/platform/mv3/scriptlets/no-settimeout-if.entity.js b/platform/mv3/scriptlets/no-settimeout-if.entity.js
index 536591111..1f5f07031 100644
--- a/platform/mv3/scriptlets/no-settimeout-if.entity.js
+++ b/platform/mv3/scriptlets/no-settimeout-if.entity.js
@@ -83,7 +83,13 @@ const scriptlet = (
                 args[0] = function(){};
             }
             return target.apply(thisArg, args);
-        }
+        },
+        get(target, prop, receiver) {
+            if ( prop === 'toString' ) {
+                return target.toString.bind(target);
+            }
+            return Reflect.get(target, prop, receiver);
+        },
     });
 };
 
diff --git a/platform/mv3/scriptlets/no-settimeout-if.js b/platform/mv3/scriptlets/no-settimeout-if.js
index 03f93d119..c2d80b6a3 100644
--- a/platform/mv3/scriptlets/no-settimeout-if.js
+++ b/platform/mv3/scriptlets/no-settimeout-if.js
@@ -83,7 +83,13 @@ const scriptlet = (
                 args[0] = function(){};
             }
             return target.apply(thisArg, args);
-        }
+        },
+        get(target, prop, receiver) {
+            if ( prop === 'toString' ) {
+                return target.toString.bind(target);
+            }
+            return Reflect.get(target, prop, receiver);
+        },
     });
 };
 
diff --git a/platform/mv3/scriptlets/set-constant.entity.js b/platform/mv3/scriptlets/set-constant.entity.js
index d758ef7f7..dacb05bbe 100644
--- a/platform/mv3/scriptlets/set-constant.entity.js
+++ b/platform/mv3/scriptlets/set-constant.entity.js
@@ -47,159 +47,240 @@ const entitiesMap = new Map(self.$entitiesMap$);
 
 /******************************************************************************/
 
-const scriptlet = (
-    chain = '',
-    cValue = ''
-) => {
-    if ( chain === '' ) { return; }
-    const trappedProp = (( ) => {
-        const pos = chain.lastIndexOf('.');
-        if ( pos === -1 ) { return chain; }
-        return chain.slice(pos+1);
-    })();
-    if ( trappedProp === '' ) { return; }
-    const objectDefineProperty = Object.defineProperty.bind(Object);
-    const cloakFunc = fn => {
-        objectDefineProperty(fn, 'name', { value: trappedProp });
-        const proxy = new Proxy(fn, {
-            defineProperty(target, prop) {
-                if ( prop !== 'toString' ) {
-                    return Reflect.deleteProperty(...arguments);
-                }
-                return true;
-            },
-            deleteProperty(target, prop) {
-                if ( prop !== 'toString' ) {
-                    return Reflect.deleteProperty(...arguments);
-                }
-                return true;
-            },
-            get(target, prop) {
-                if ( prop === 'toString' ) {
-                    return function() {
-                        return `function ${trappedProp}() { [native code] }`;
-                    }.bind(null);
-                }
-                return Reflect.get(...arguments);
-            },
-        });
-        return proxy;
-    };
-    if ( cValue === 'undefined' ) {
-        cValue = undefined;
-    } else if ( cValue === 'false' ) {
-        cValue = false;
-    } else if ( cValue === 'true' ) {
-        cValue = true;
-    } else if ( cValue === 'null' ) {
-        cValue = null;
-    } else if ( cValue === "''" ) {
-        cValue = '';
-    } else if ( cValue === '[]' ) {
-        cValue = [];
-    } else if ( cValue === '{}' ) {
-        cValue = {};
-    } else if ( cValue === 'noopFunc' ) {
-        cValue = cloakFunc(function(){});
-    } else if ( cValue === 'trueFunc' ) {
-        cValue = cloakFunc(function(){ return true; });
-    } else if ( cValue === 'falseFunc' ) {
-        cValue = cloakFunc(function(){ return false; });
-    } else if ( /^\d+$/.test(cValue) ) {
-        cValue = parseFloat(cValue);
-        if ( isNaN(cValue) ) { return; }
-        if ( Math.abs(cValue) > 0x7FFF ) { return; }
-    } else {
-        return;
+// Dependencies
+
+const scriptletGlobals = new Map();
+
+function safeSelf() {
+    if ( scriptletGlobals.has('safeSelf') ) {
+        return scriptletGlobals.get('safeSelf');
     }
-    let aborted = false;
-    const mustAbort = function(v) {
-        if ( aborted ) { return true; }
-        aborted =
-            (v !== undefined && v !== null) &&
-            (cValue !== undefined && cValue !== null) &&
-            (typeof v !== typeof cValue);
-        return aborted;
+    const safe = {
+        'RegExp': self.RegExp,
+        'RegExp_test': self.RegExp.prototype.test,
+        'RegExp_exec': self.RegExp.prototype.exec,
+        'addEventListener': self.EventTarget.prototype.addEventListener,
+        'removeEventListener': self.EventTarget.prototype.removeEventListener,
     };
-    // https://github.com/uBlockOrigin/uBlock-issues/issues/156
-    //   Support multiple trappers for the same property.
-    const trapProp = function(owner, prop, configurable, handler) {
-        if ( handler.init(owner[prop]) === false ) { return; }
-        const odesc = Object.getOwnPropertyDescriptor(owner, prop);
-        let prevGetter, prevSetter;
-        if ( odesc instanceof Object ) {
-            owner[prop] = cValue;
-            if ( odesc.get instanceof Function ) {
-                prevGetter = odesc.get;
-            }
-            if ( odesc.set instanceof Function ) {
-                prevSetter = odesc.set;
-            }
+    scriptletGlobals.set('safeSelf', safe);
+    return safe;
+}
+
+function runAt(fn, when) {
+    const intFromReadyState = state => {
+        const targets = {
+            'loading': 1,
+            'interactive': 2, 'end': 2, '2': 2,
+            'complete': 3, 'idle': 3, '3': 3,
+        };
+        const tokens = Array.isArray(state) ? state : [ state ];
+        for ( const token of tokens ) {
+            const prop = `${token}`;
+            if ( targets.hasOwnProperty(prop) === false ) { continue; }
+            return targets[prop];
         }
-        try {
-            objectDefineProperty(owner, prop, {
-                configurable,
-                get() {
-                    if ( prevGetter !== undefined ) {
-                        prevGetter();
+        return 0;
+    };
+    const runAt = intFromReadyState(when);
+    if ( intFromReadyState(document.readyState) >= runAt ) {
+        fn(); return;
+    }
+    const onStateChange = ( ) => {
+        if ( intFromReadyState(document.readyState) < runAt ) { return; }
+        fn();
+        safe.removeEventListener.apply(document, args);
+    };
+    const safe = safeSelf();
+    const args = [ 'readystatechange', onStateChange, { capture: true } ];
+    safe.addEventListener.apply(document, args);
+}
+
+/******************************************************************************/
+
+const scriptlet = (
+    arg1 = '',
+    arg2 = '',
+    arg3 = ''
+) => {
+    const details = typeof arg1 !== 'object'
+        ? { prop: arg1, value: arg2 }
+        : arg1;
+    if ( arg3 !== '' ) {
+        if ( /^\d$/.test(arg3) ) {
+            details.options = [ arg3 ];
+        } else {
+            details.options = Array.from(arguments).slice(2);
+        }
+    }
+    const { prop: chain = '', value: cValue = '' } = details;
+    if ( typeof chain !== 'string' ) { return; }
+    if ( chain === '' ) { return; }
+    const options = details.options || [];
+    function setConstant(chain, cValue) {
+        const trappedProp = (( ) => {
+            const pos = chain.lastIndexOf('.');
+            if ( pos === -1 ) { return chain; }
+            return chain.slice(pos+1);
+        })();
+        if ( trappedProp === '' ) { return; }
+        const thisScript = document.currentScript;
+        const objectDefineProperty = Object.defineProperty.bind(Object);
+        const cloakFunc = fn => {
+            objectDefineProperty(fn, 'name', { value: trappedProp });
+            const proxy = new Proxy(fn, {
+                defineProperty(target, prop) {
+                    if ( prop !== 'toString' ) {
+                        return Reflect.deleteProperty(...arguments);
                     }
-                    return handler.getter(); // cValue
+                    return true;
                 },
-                set(a) {
-                    if ( prevSetter !== undefined ) {
-                        prevSetter(a);
+                deleteProperty(target, prop) {
+                    if ( prop !== 'toString' ) {
+                        return Reflect.deleteProperty(...arguments);
                     }
-                    handler.setter(a);
-                }
+                    return true;
+                },
+                get(target, prop) {
+                    if ( prop === 'toString' ) {
+                        return function() {
+                            return `function ${trappedProp}() { [native code] }`;
+                        }.bind(null);
+                    }
+                    return Reflect.get(...arguments);
+                },
             });
-        } catch(ex) {
+            return proxy;
+        };
+        if ( cValue === 'undefined' ) {
+            cValue = undefined;
+        } else if ( cValue === 'false' ) {
+            cValue = false;
+        } else if ( cValue === 'true' ) {
+            cValue = true;
+        } else if ( cValue === 'null' ) {
+            cValue = null;
+        } else if ( cValue === "''" ) {
+            cValue = '';
+        } else if ( cValue === '[]' ) {
+            cValue = [];
+        } else if ( cValue === '{}' ) {
+            cValue = {};
+        } else if ( cValue === 'noopFunc' ) {
+            cValue = cloakFunc(function(){});
+        } else if ( cValue === 'trueFunc' ) {
+            cValue = cloakFunc(function(){ return true; });
+        } else if ( cValue === 'falseFunc' ) {
+            cValue = cloakFunc(function(){ return false; });
+        } else if ( /^-?\d+$/.test(cValue) ) {
+            cValue = parseInt(cValue);
+            if ( isNaN(cValue) ) { return; }
+            if ( Math.abs(cValue) > 0x7FFF ) { return; }
+        } else {
+            return;
         }
-    };
-    const trapChain = function(owner, chain) {
-        const pos = chain.indexOf('.');
-        if ( pos === -1 ) {
-            trapProp(owner, chain, false, {
+        if ( options.includes('asFunction') ) {
+            cValue = ( ) => cValue;
+        } else if ( options.includes('asCallback') ) {
+            cValue = ( ) => (( ) => cValue);
+        } else if ( options.includes('asResolved') ) {
+            cValue = Promise.resolve(cValue);
+        } else if ( options.includes('asRejected') ) {
+            cValue = Promise.reject(cValue);
+        }
+        let aborted = false;
+        const mustAbort = function(v) {
+            if ( aborted ) { return true; }
+            aborted =
+                (v !== undefined && v !== null) &&
+                (cValue !== undefined && cValue !== null) &&
+                (typeof v !== typeof cValue);
+            return aborted;
+        };
+        // https://github.com/uBlockOrigin/uBlock-issues/issues/156
+        //   Support multiple trappers for the same property.
+        const trapProp = function(owner, prop, configurable, handler) {
+            if ( handler.init(configurable ? owner[prop] : cValue) === false ) { return; }
+            const odesc = Object.getOwnPropertyDescriptor(owner, prop);
+            let prevGetter, prevSetter;
+            if ( odesc instanceof Object ) {
+                owner[prop] = cValue;
+                if ( odesc.get instanceof Function ) {
+                    prevGetter = odesc.get;
+                }
+                if ( odesc.set instanceof Function ) {
+                    prevSetter = odesc.set;
+                }
+            }
+            try {
+                objectDefineProperty(owner, prop, {
+                    configurable,
+                    get() {
+                        if ( prevGetter !== undefined ) {
+                            prevGetter();
+                        }
+                        return handler.getter(); // cValue
+                    },
+                    set(a) {
+                        if ( prevSetter !== undefined ) {
+                            prevSetter(a);
+                        }
+                        handler.setter(a);
+                    }
+                });
+            } catch(ex) {
+            }
+        };
+        const trapChain = function(owner, chain) {
+            const pos = chain.indexOf('.');
+            if ( pos === -1 ) {
+                trapProp(owner, chain, false, {
+                    v: undefined,
+                    init: function(v) {
+                        if ( mustAbort(v) ) { return false; }
+                        this.v = v;
+                        return true;
+                    },
+                    getter: function() {
+                        return document.currentScript === thisScript
+                            ? this.v
+                            : cValue;
+                    },
+                    setter: function(a) {
+                        if ( mustAbort(a) === false ) { return; }
+                        cValue = a;
+                    }
+                });
+                return;
+            }
+            const prop = chain.slice(0, pos);
+            const v = owner[prop];
+            chain = chain.slice(pos + 1);
+            if ( v instanceof Object || typeof v === 'object' && v !== null ) {
+                trapChain(v, chain);
+                return;
+            }
+            trapProp(owner, prop, true, {
                 v: undefined,
                 init: function(v) {
-                    if ( mustAbort(v) ) { return false; }
                     this.v = v;
                     return true;
                 },
                 getter: function() {
-                    return cValue;
+                    return this.v;
                 },
                 setter: function(a) {
-                    if ( mustAbort(a) === false ) { return; }
-                    cValue = a;
+                    this.v = a;
+                    if ( a instanceof Object ) {
+                        trapChain(a, chain);
+                    }
                 }
             });
-            return;
-        }
-        const prop = chain.slice(0, pos);
-        const v = owner[prop];
-        chain = chain.slice(pos + 1);
-        if ( v instanceof Object || typeof v === 'object' && v !== null ) {
-            trapChain(v, chain);
-            return;
-        }
-        trapProp(owner, prop, true, {
-            v: undefined,
-            init: function(v) {
-                this.v = v;
-                return true;
-            },
-            getter: function() {
-                return this.v;
-            },
-            setter: function(a) {
-                this.v = a;
-                if ( a instanceof Object ) {
-                    trapChain(a, chain);
-                }
-            }
-        });
-    };
-    trapChain(window, chain);
+        };
+        trapChain(window, chain);
+    }
+    runAt(( ) => {
+        setConstant(chain, cValue);
+    }, options);
 };
 
 /******************************************************************************/
diff --git a/platform/mv3/scriptlets/set-constant.js b/platform/mv3/scriptlets/set-constant.js
index dc714c844..6652cbee9 100644
--- a/platform/mv3/scriptlets/set-constant.js
+++ b/platform/mv3/scriptlets/set-constant.js
@@ -47,159 +47,240 @@ const hostnamesMap = new Map(self.$hostnamesMap$);
 
 /******************************************************************************/
 
-const scriptlet = (
-    chain = '',
-    cValue = ''
-) => {
-    if ( chain === '' ) { return; }
-    const trappedProp = (( ) => {
-        const pos = chain.lastIndexOf('.');
-        if ( pos === -1 ) { return chain; }
-        return chain.slice(pos+1);
-    })();
-    if ( trappedProp === '' ) { return; }
-    const objectDefineProperty = Object.defineProperty.bind(Object);
-    const cloakFunc = fn => {
-        objectDefineProperty(fn, 'name', { value: trappedProp });
-        const proxy = new Proxy(fn, {
-            defineProperty(target, prop) {
-                if ( prop !== 'toString' ) {
-                    return Reflect.deleteProperty(...arguments);
-                }
-                return true;
-            },
-            deleteProperty(target, prop) {
-                if ( prop !== 'toString' ) {
-                    return Reflect.deleteProperty(...arguments);
-                }
-                return true;
-            },
-            get(target, prop) {
-                if ( prop === 'toString' ) {
-                    return function() {
-                        return `function ${trappedProp}() { [native code] }`;
-                    }.bind(null);
-                }
-                return Reflect.get(...arguments);
-            },
-        });
-        return proxy;
-    };
-    if ( cValue === 'undefined' ) {
-        cValue = undefined;
-    } else if ( cValue === 'false' ) {
-        cValue = false;
-    } else if ( cValue === 'true' ) {
-        cValue = true;
-    } else if ( cValue === 'null' ) {
-        cValue = null;
-    } else if ( cValue === "''" ) {
-        cValue = '';
-    } else if ( cValue === '[]' ) {
-        cValue = [];
-    } else if ( cValue === '{}' ) {
-        cValue = {};
-    } else if ( cValue === 'noopFunc' ) {
-        cValue = cloakFunc(function(){});
-    } else if ( cValue === 'trueFunc' ) {
-        cValue = cloakFunc(function(){ return true; });
-    } else if ( cValue === 'falseFunc' ) {
-        cValue = cloakFunc(function(){ return false; });
-    } else if ( /^\d+$/.test(cValue) ) {
-        cValue = parseFloat(cValue);
-        if ( isNaN(cValue) ) { return; }
-        if ( Math.abs(cValue) > 0x7FFF ) { return; }
-    } else {
-        return;
+// Dependencies
+
+const scriptletGlobals = new Map();
+
+function safeSelf() {
+    if ( scriptletGlobals.has('safeSelf') ) {
+        return scriptletGlobals.get('safeSelf');
     }
-    let aborted = false;
-    const mustAbort = function(v) {
-        if ( aborted ) { return true; }
-        aborted =
-            (v !== undefined && v !== null) &&
-            (cValue !== undefined && cValue !== null) &&
-            (typeof v !== typeof cValue);
-        return aborted;
+    const safe = {
+        'RegExp': self.RegExp,
+        'RegExp_test': self.RegExp.prototype.test,
+        'RegExp_exec': self.RegExp.prototype.exec,
+        'addEventListener': self.EventTarget.prototype.addEventListener,
+        'removeEventListener': self.EventTarget.prototype.removeEventListener,
     };
-    // https://github.com/uBlockOrigin/uBlock-issues/issues/156
-    //   Support multiple trappers for the same property.
-    const trapProp = function(owner, prop, configurable, handler) {
-        if ( handler.init(owner[prop]) === false ) { return; }
-        const odesc = Object.getOwnPropertyDescriptor(owner, prop);
-        let prevGetter, prevSetter;
-        if ( odesc instanceof Object ) {
-            owner[prop] = cValue;
-            if ( odesc.get instanceof Function ) {
-                prevGetter = odesc.get;
-            }
-            if ( odesc.set instanceof Function ) {
-                prevSetter = odesc.set;
-            }
+    scriptletGlobals.set('safeSelf', safe);
+    return safe;
+}
+
+function runAt(fn, when) {
+    const intFromReadyState = state => {
+        const targets = {
+            'loading': 1,
+            'interactive': 2, 'end': 2, '2': 2,
+            'complete': 3, 'idle': 3, '3': 3,
+        };
+        const tokens = Array.isArray(state) ? state : [ state ];
+        for ( const token of tokens ) {
+            const prop = `${token}`;
+            if ( targets.hasOwnProperty(prop) === false ) { continue; }
+            return targets[prop];
         }
-        try {
-            objectDefineProperty(owner, prop, {
-                configurable,
-                get() {
-                    if ( prevGetter !== undefined ) {
-                        prevGetter();
+        return 0;
+    };
+    const runAt = intFromReadyState(when);
+    if ( intFromReadyState(document.readyState) >= runAt ) {
+        fn(); return;
+    }
+    const onStateChange = ( ) => {
+        if ( intFromReadyState(document.readyState) < runAt ) { return; }
+        fn();
+        safe.removeEventListener.apply(document, args);
+    };
+    const safe = safeSelf();
+    const args = [ 'readystatechange', onStateChange, { capture: true } ];
+    safe.addEventListener.apply(document, args);
+}
+
+/******************************************************************************/
+
+const scriptlet = (
+    arg1 = '',
+    arg2 = '',
+    arg3 = ''
+) => {
+    const details = typeof arg1 !== 'object'
+        ? { prop: arg1, value: arg2 }
+        : arg1;
+    if ( arg3 !== '' ) {
+        if ( /^\d$/.test(arg3) ) {
+            details.options = [ arg3 ];
+        } else {
+            details.options = Array.from(arguments).slice(2);
+        }
+    }
+    const { prop: chain = '', value: cValue = '' } = details;
+    if ( typeof chain !== 'string' ) { return; }
+    if ( chain === '' ) { return; }
+    const options = details.options || [];
+    function setConstant(chain, cValue) {
+        const trappedProp = (( ) => {
+            const pos = chain.lastIndexOf('.');
+            if ( pos === -1 ) { return chain; }
+            return chain.slice(pos+1);
+        })();
+        if ( trappedProp === '' ) { return; }
+        const thisScript = document.currentScript;
+        const objectDefineProperty = Object.defineProperty.bind(Object);
+        const cloakFunc = fn => {
+            objectDefineProperty(fn, 'name', { value: trappedProp });
+            const proxy = new Proxy(fn, {
+                defineProperty(target, prop) {
+                    if ( prop !== 'toString' ) {
+                        return Reflect.deleteProperty(...arguments);
                     }
-                    return handler.getter(); // cValue
+                    return true;
                 },
-                set(a) {
-                    if ( prevSetter !== undefined ) {
-                        prevSetter(a);
+                deleteProperty(target, prop) {
+                    if ( prop !== 'toString' ) {
+                        return Reflect.deleteProperty(...arguments);
                     }
-                    handler.setter(a);
-                }
+                    return true;
+                },
+                get(target, prop) {
+                    if ( prop === 'toString' ) {
+                        return function() {
+                            return `function ${trappedProp}() { [native code] }`;
+                        }.bind(null);
+                    }
+                    return Reflect.get(...arguments);
+                },
             });
-        } catch(ex) {
+            return proxy;
+        };
+        if ( cValue === 'undefined' ) {
+            cValue = undefined;
+        } else if ( cValue === 'false' ) {
+            cValue = false;
+        } else if ( cValue === 'true' ) {
+            cValue = true;
+        } else if ( cValue === 'null' ) {
+            cValue = null;
+        } else if ( cValue === "''" ) {
+            cValue = '';
+        } else if ( cValue === '[]' ) {
+            cValue = [];
+        } else if ( cValue === '{}' ) {
+            cValue = {};
+        } else if ( cValue === 'noopFunc' ) {
+            cValue = cloakFunc(function(){});
+        } else if ( cValue === 'trueFunc' ) {
+            cValue = cloakFunc(function(){ return true; });
+        } else if ( cValue === 'falseFunc' ) {
+            cValue = cloakFunc(function(){ return false; });
+        } else if ( /^-?\d+$/.test(cValue) ) {
+            cValue = parseInt(cValue);
+            if ( isNaN(cValue) ) { return; }
+            if ( Math.abs(cValue) > 0x7FFF ) { return; }
+        } else {
+            return;
         }
-    };
-    const trapChain = function(owner, chain) {
-        const pos = chain.indexOf('.');
-        if ( pos === -1 ) {
-            trapProp(owner, chain, false, {
+        if ( options.includes('asFunction') ) {
+            cValue = ( ) => cValue;
+        } else if ( options.includes('asCallback') ) {
+            cValue = ( ) => (( ) => cValue);
+        } else if ( options.includes('asResolved') ) {
+            cValue = Promise.resolve(cValue);
+        } else if ( options.includes('asRejected') ) {
+            cValue = Promise.reject(cValue);
+        }
+        let aborted = false;
+        const mustAbort = function(v) {
+            if ( aborted ) { return true; }
+            aborted =
+                (v !== undefined && v !== null) &&
+                (cValue !== undefined && cValue !== null) &&
+                (typeof v !== typeof cValue);
+            return aborted;
+        };
+        // https://github.com/uBlockOrigin/uBlock-issues/issues/156
+        //   Support multiple trappers for the same property.
+        const trapProp = function(owner, prop, configurable, handler) {
+            if ( handler.init(configurable ? owner[prop] : cValue) === false ) { return; }
+            const odesc = Object.getOwnPropertyDescriptor(owner, prop);
+            let prevGetter, prevSetter;
+            if ( odesc instanceof Object ) {
+                owner[prop] = cValue;
+                if ( odesc.get instanceof Function ) {
+                    prevGetter = odesc.get;
+                }
+                if ( odesc.set instanceof Function ) {
+                    prevSetter = odesc.set;
+                }
+            }
+            try {
+                objectDefineProperty(owner, prop, {
+                    configurable,
+                    get() {
+                        if ( prevGetter !== undefined ) {
+                            prevGetter();
+                        }
+                        return handler.getter(); // cValue
+                    },
+                    set(a) {
+                        if ( prevSetter !== undefined ) {
+                            prevSetter(a);
+                        }
+                        handler.setter(a);
+                    }
+                });
+            } catch(ex) {
+            }
+        };
+        const trapChain = function(owner, chain) {
+            const pos = chain.indexOf('.');
+            if ( pos === -1 ) {
+                trapProp(owner, chain, false, {
+                    v: undefined,
+                    init: function(v) {
+                        if ( mustAbort(v) ) { return false; }
+                        this.v = v;
+                        return true;
+                    },
+                    getter: function() {
+                        return document.currentScript === thisScript
+                            ? this.v
+                            : cValue;
+                    },
+                    setter: function(a) {
+                        if ( mustAbort(a) === false ) { return; }
+                        cValue = a;
+                    }
+                });
+                return;
+            }
+            const prop = chain.slice(0, pos);
+            const v = owner[prop];
+            chain = chain.slice(pos + 1);
+            if ( v instanceof Object || typeof v === 'object' && v !== null ) {
+                trapChain(v, chain);
+                return;
+            }
+            trapProp(owner, prop, true, {
                 v: undefined,
                 init: function(v) {
-                    if ( mustAbort(v) ) { return false; }
                     this.v = v;
                     return true;
                 },
                 getter: function() {
-                    return cValue;
+                    return this.v;
                 },
                 setter: function(a) {
-                    if ( mustAbort(a) === false ) { return; }
-                    cValue = a;
+                    this.v = a;
+                    if ( a instanceof Object ) {
+                        trapChain(a, chain);
+                    }
                 }
             });
-            return;
-        }
-        const prop = chain.slice(0, pos);
-        const v = owner[prop];
-        chain = chain.slice(pos + 1);
-        if ( v instanceof Object || typeof v === 'object' && v !== null ) {
-            trapChain(v, chain);
-            return;
-        }
-        trapProp(owner, prop, true, {
-            v: undefined,
-            init: function(v) {
-                this.v = v;
-                return true;
-            },
-            getter: function() {
-                return this.v;
-            },
-            setter: function(a) {
-                this.v = a;
-                if ( a instanceof Object ) {
-                    trapChain(a, chain);
-                }
-            }
-        });
-    };
-    trapChain(window, chain);
+        };
+        trapChain(window, chain);
+    }
+    runAt(( ) => {
+        setConstant(chain, cValue);
+    }, options);
 };
 
 /******************************************************************************/