Hmm ... if he is moving to watch you on the stand, then he doesn’t really get “STAY” yet, so I would work more on that piece before trying to walk around him. One thing that can be helpful is to put gentle tension on a buckle collar while reminding them to stay - it helps them learn to fight to stay in position. Once he’s good at that, you can practice moving from side to side in from of him, and rewarding that, gradually extending how far around you go. If he moves, reposition him with a verbal correction “I said STAY” and try again.
As for heeling backwards, that took Chloe forever to learn, but it is helpful to do it next to a wall so they can’t swing out of position, and just keep encouraging him to “back”, praising when he gets it. Has he learned attention in heel position? We do something called a moving watch, where they learn to watch our faces while we move around, so they learn they need to move when we do in order to maintain eye contact (spitting treats helps with this). We do this as a first step before teaching heeling, but it comes in handy when we want to teach the backing up, as they already know they need to keep watching us and as we back up they already know they need to move to maintain eye contact ... doing it next to a wall teaches them HOW to move to keep watching us (i.e. to back up rather than turn around towards us).