I'm not sure what all the different checks are currently, but one check should be perfectly clear.
If nobody on your team has died by 3 minutes, and you have a teammate who has not left the fountain, a remake should be possible.
It shouldn't matter if they are trying to connect. It shouldn't matter if they connected for a bit and then left. It shouldn't matter if the game recognizes them as being in game.
This doesn't fix all remake scenarios that need adjustment, but this should be an automatic remake scenario. If a player cannot or does not leave base by 3 minutes, and nobody on your team has died, penalize the player who is AFK or DC rather than the entire team.