On Lineage OS (and maybe on any Android?), it is possible to change the default WebView render (which is set by default to AOSP Browser, the default android browser without GAPPS). When I install Chrome (even without GAPPS installed), I can change this default to Chrome in the Setting/Development (which is practical in my case as the default browser has some annoying bugs).
Is it possible to also use Firefox's engine instead of Browser/Chrome (I don't want to have chrome installed and rely on proprietary software)? Installing Firefox (Fennec on FDroid) is not enough.
Thanks!
This is not possible because GeckoView does not implement the WebView API according to one of the authors.
https://github.com/mozilla/geckoview/issues/167#issuecomment-902022285