Purely as a low-effort attempt at a humorous argument, if you accept user groups in opening_hours:*= , this could be interpreted as when the beaches or pools are open to lifeguards Key:opening_hours:lifeguard - OpenStreetMap Wiki (should be changed to lifeguard:conditional= )
I don’t see a reason to complicate the opening_hours:*= format with something that has only 2 dozens use. Mixing up different aspects is never good a idea. If standardization and support are desired, commented opening_hours= already work best.