I have been using Cookie AutoDelete like this for probably more than a year now and it has been working fine as far as I can tell.
Mozilla presumably has a somewhat different opinion, though, otherwise they would have probably added it to the officially supported extension by now. For example, it might drain battery life or something similar, which I wouldn’t be able to tell with my naive usage.
Well, you can get it installed via a workaround.
You need either Firefox Nightly or an official Firefox build (like Fennec, Mull etc.). And then follow these instructions: https://blog.mozilla.org/addons/2020/09/29/expanded-extension-support-in-firefox-for-android-nightly/
I have been using Cookie AutoDelete like this for probably more than a year now and it has been working fine as far as I can tell.
Mozilla presumably has a somewhat different opinion, though, otherwise they would have probably added it to the officially supported extension by now. For example, it might drain battery life or something similar, which I wouldn’t be able to tell with my naive usage.