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?
It’s always a good idea to stick with pure firefox instead of using unknown browsers that may be discontinued abruptly in the future.
You’re right about being cautious that they might be discontinued, but you can always port them to another Firefox port. Also this is a fork from Firefox stable and applies patches to it, so not a ton of custom code needs to be done.
Not possible on mobile though. On Desktop I am working on Arkenfox-softening that modifies the arkenfox user.js and makes updates easier.