Paizocon which required vaccines, and boosters along with mask, had a covid outbreak. 9 known cases so far for a convention of 500. They even limited the convention and certain events. Goes to show you that a convention can believe they're trying to be as safe as possible with restrictions and still have issues.
Whats the point, they limited who can attend because of the vax/booster requirement, and detracted from the fun of the attendees with mask wearing and still had issues. Covid is not going anywhere until there is a vaccine that actually stops transmission.
If you are that concerned you might catch covid that you want restrictions placed on your fellow attendees, or even limit who can attend because they are not vaxed, you should probably not be attending conventions. The convention organizers need to quit worrying about it with these restrictions. Paizocon proved an outbreak can/will happen anywhere no matter what precautions are taken. Just make everyone sign a waiver and that you understand you attend at your own risk. No one is forcing an attendee to go to a convention.