There’s a lot of things that you can’t wear due to particular mutations, however ultimately it doesn’t make much sense that you can’t just modify clothing to allow it. If you can make holes for your neck, arms, and waist, why not just have one extra hole for a tail? Wings? Have a bigger hole on your back.
As a side effect of all this (and balance), they tend to be harder to make, require slightly different materials, may have less coverage, etc.
Due to how inherently different compensating for various types of mutated anatomy is, it might make sense to have a proficiency based off of it. There’s probably a better name for it but something like ‘Mutant Compatibility Design’ should suffice.
EDIT: Forgot to mention that if this is found as an acceptable addition I’ll gladly work on a lot of it myself. I’ll need to remember how to make everything but I know where to look to find everything. The only thing I don’t know how to do is make a new proficiency, so if anyone could do that as well real quick that’d be great. Ultimately, this could be put into a mod if for some reason it’s not considered acceptable into the base game, but that’d be much less ideal and it wouldn’t be quite so supported then.