I will not be forced to wear a mask in public. Period. Non-negotiable.
I can't find any decent legal resources via Google short of the consensus that if you claim a disability through the ADA nobody can legally question it.
Does anyone here have any experience with this, or any legal information resources available?
Just don't wear it. Read your counties specific EO to learn the exceptions. Ours says you qualify for a medical exception if you "have a hard time breathing" wearing the mask. No documentation needed. Now, businesses don't have to allow you access - that's their prerogative. I've never had any business say anything.