common, I’ll be interested to learn about ranges of halakha here. I don’t know exact answer. You said several times “what if the answer does not fit” without providing any halakhic references, this does not help me at all.
I am also not sure “exercising rights under US law” concludes halakhic discussion. I understand you are involved into ADA, but how does it affect possible moris ayn? Maybe you can have a sign “no mask based on ADA”. Maybe also wearing a face shield could show people that you are not a total rasha – with an ADA sticker to boot.