Hello @Ron-and-Laurie0
So frustrating what you are going through - remember having the same scenario from a host when I first started out😩 - they had terrible reviews and having refused once his reservation, they came back to reserve a second time. Ended up blocking him and calling Customer Service. Hard to believe that CS won't do anything to help you when it is clear that this future guest is going to break your house rules by exceeding your maximum guest count. Will that mean that you won't be covered if there is a problem? It just doesn't make sense.
Found this earlier conversation on very much the same issue which you might find helpful:
https://community.withairbnb.com/t5/Community-Cafe/declining-requests/m-p/1551051#:~:text=If%20you%2....
Hopefully @Helen3 advice on blocking this guest will do the trick but have also read about hosts blocking a day or two on their calendar that will render this stay "unavailable". Then a few days later, they unblock the dates.
Has this reservation been confirmed yet or you still at the stage that you have time left to either accept or decline? If you have pushed the toggle that says that you require your guests to have a proper profile picture of themselves in the Guest preferences section and they haven't done so then this means that you can get Airbnb to cancel the reservation penalty free. This is on top of your house rules.
Fingers crossed for you
Joëlle