if you want to start a big FFA this system would still work. in fact it would greatly reduce wait time for the first turn if the boot time is 10minutes as the pop up will only be there for about 1 to 2min. everyone that hasnt accepted the pop will be replaced by an open seat.
Yes, but then the whole thing resets, right? Let's say you want to start a 20-player FFA. Four people fail to hit the pop-up, so they're replaced with open seats. Now you have to wait for four more people. Once they join, everyone needs to hit the pop-up. One person fails to hit it. Now you have to wait for one more person to join and another 1-2 minute pop-up. The more people you have in a game with that system, the less likely it becomes to start.