If the host only syncs players together ... could it not also keep track of what players/ICO accounts are in the game ... and when the player tries to rejoin, see that the account was in the game 5 minutes or less ago or something? As far as I know you can't see games in progress on ICO... maybe that could also be changed?
How does the host keep the computers in sync? Could it not just update the rejoining computer with the latest gamestate information?
I don't know anything about p2p or networking, I just play games lol, so just asking