What about simplex? It looks like it uses random message queues for each connection (contact) and once deleted from devices then it doesn't look likethere is any solid way of identifying if a connection existed...
(NB: simplex don't have an account for a user in their cloud at all because of how it works so recovery is impossible without latest backups, so that's a no go for me)
Mine should have a 3070ti so ut should have no excuse for NOT running DOOM.