@Doing my best………
BUT that is not what you posted. You can’t expect CR participants to be mind readers..
That said I doubt the courts would consider it trespassing. The call for shoppers is a general invitation to the public and a storekeeper can refuse service or entry to an individual. BUT, it would require personal notification by the store personnel to the individual. It is too easy for the non-mask wearing shopper to say: “I didn’t see or read the sign” or “I don’t read (Pick a language).
An unlocked store with posted hours, lights on and a sign over the storefront (as well as advertising) create the general invitation to the public. The entry is not trespassing, but non-compliance with the posted rule is reason to ask the person to leave.