Not to tell you & your friends how to live your lives, but from what I understand, covid transmission from aerosols from adjacent parties is not really a thing outdoors (3-6' away). Just being outdoors itself is the key. Wearing clear face shields that block whatever little spittle is produced when talking should take care of the rest. And they have probably had 3-4 vaccines by now, therapeutics have taken a giant leap forward in the past two years, and infection rates are low in the county. Are they going to hide for the rest of their lives ? I understand that sometimes its more comforting to manage the psychology instead of the actual risks, like continuing to wear a non-N95 cloth face mask indoors at the public library.