Not really, and the reason is that everyone disagrees on what "Mozilla's BS" is - e.g. some say not enabling full protection is BS. Some say it's fine for Mozilla to know what hardware Firefox crashes most on, some say it's none of its business.

But honestly, it's possible to disable almost everything you don't like in Firefox, and it's usually just a toggle. So I think the easiest option is to just do that whenever you run into something you don't like. The alternative is doing it the other way around, i.e. starting with e.g. Librewolf and then undoing their tweaks if you don't like them, but it's harder to know what tweak is responsible for breaking a website you use, for example.