I have resolved it.
Scriptish will insert a toolbar button to browser windows. And every time it wants to inject a script, it checks if the target is alive and if it has Scriptish's UI, if not, it just return.
As a result, although it supports chrome
scheme, it only inject scripts into browser windows and chrome page in tabs.
I edited modules\utils\Scriptish_injectScripts.js
, removed this check at line 29, now it can inject scripts as their @include
meta data.