Since you mentioned Tridactyl you might be interested to know that I wrote my own command to inject Google Translate on demand [3].
The extensions you mentioned were removed because they execute remote code. Mozilla are trying to tighten these restrictions [4]. I think Chrome is moving in a similar direction. I don't think that will affect the user script work-around as they execute in the page context, but I could be wrong.
[1]: https://addons.mozilla.org/en-US/firefox/addon/violentmonkey...
[2]: https://greasyfork.org/en/scripts/9285-translate-google-tool...
[3]: https://github.com/tridactyl/tridactyl/blob/c776f722944714ee...
[4]: https://blog.mozilla.org/addons/2019/12/12/test-the-new-csp-...
[1]: https://github.com/violentmonkey/violentmonkey/graphs/contri...
[2]: https://github.com/greasemonkey/greasemonkey/graphs/contribu...
So you pretty much have to have Chromium as a backup if you ever need to research non-Anglo content.
I can see people moving to Chromium because of this and other similar problems with extensions being broken (like the tridactyl thing).