FWIW, even though it is annoying as hell, you may override the extension compatibility on Firefox for Android. https://blog.mozilla.org/addons/2020/09/29/expan

FWIW, even though it is annoying as hell, you may override the extension compatibility on Firefox for Android. https://blog.mozilla.org/addons/2020/09/29/expanded-extension-support-in-firefox-for-android-nightly/ https://blog.mozilla.org/addons/2020/09/29/expanded-extensio... This suggests it only works in Nightly, but it also works in Fennec F-Droid, so frankly you should consider switching to that if you can. (I wish Fennec F-Droid could just allow arbitrary extensions and extension side-loading, but I guess it would be non-trivial. Thanks Mozilla!)