Is it correct that the Firefox uBlock Origin doesn't need the companion as it already supports WebSockets filtering?
There is also a note on the normal uBlock repo that says that Firefox has an extra feature with a link to inline script tag filtering, which says it does not work on Chromium based brownsers: https://github.com/gorhill/uBlock/wiki/Inline-script-tag-fil...
Per-inline script tag filtering is possible for Firefox, but the feature relies on "beforescriptexecute", which is planned to be deprecated in Firefox as well[1]. As a result I have ceased to create "script:contains" filters and favor filter solutions which work on all browsers.