It’s generally fine, the vast majority of applications are fine with it, it’s mainly the legacy shit that falls over.
You can also enable it on a per directory basis, and I’ve yet to encounter a Dev tool that has issues with it. Same for the path limit, you can have long paths enabled too.
This is the way to do it - actual valid certs, with actual working TLS.
OP’s issue is they don’t understand how SSL works and fighting Firefox, which is actually trying to protect them and steer they e in the right direction.