Quote:when I'm alt tabbed for any length of time I come back to find the character at the join screenI've just tested the length of time after which the game disappears if you don't do anything, it seems to be 30 minutes. (after 29 minutes, 30 seconds, game was still on, after 31 minutes, back in lobby; these were separate tests as I moved* the character after the 29 minute 30 seconds test)
This is more than enough time to be able to "burn in" mules while doing other things at home, though perhaps not enough to conveniently burn them in while going out or while sleeping.
*what I actually did was I exited/reentered the gambling screen
and btw, I was alt tabbed the entire time (except briefly at the beginning and the end of course). I doubt that whether you're alt tabbed or not has any effect though.