I would like to ask any Firefox forks that is ideal for Android phones (Preferably Hardened ones if that's an option). Please don't recommend Chromium based browsers.
Fennec is not hardened, it removes telemetry. Ironfox is a fork of the discontinued Mull which is hardened.
You can of course harden Fennec through about:config . Using Ironfox is the better option if that's your goal though. It also has nice features like a toggle to disable SafeBrowsing.
Currently, you can install IronFox from Accrescent, from your preferred F-Droid client via our F-Droid repository, with Obtainium, or directly from our GitLab releases.