I've noticed some rare desyncs playing online, where both clients are waiting for the other to lock in while both are actually locked in locally.
I know there's a lot of edge cases where desyncs or disconnects can happen (especially on spotty internet), so it'd be nice if there was a Reconnect option. If one player is still in the match, the other player could reconnect and it would download the game state (which doesn't seem like that much to download? just variables of a dozen or so entities) and start the match from that point.