I installed the mull browser revently. People who are familiar with this will know that it’s a fork of firefox android. It’s hardened but I haven’t noticed much difference b/w the two. Mull has a few visible tweaks like Https mode by default, strict protection etc. but I haven’t come across other backend/not so visible changes. How is it different from firefox android?
Not possible on mobile though. On Desktop I am working on Arkenfox-softening that modifies the arkenfox user.js and makes updates easier.