Queue Pop Constant Withdraw Syndrome: For those who abuse this trying to get in a "in-progress" should get a 3 to 5 minute lockout timer until they can queue again.
For some people they do miss the timer and isn't intention, your idea would hurt them as to where mine would not.

Bad solution. If they don't know if they're joining in progress, then people won't do it. People who need to replace a member will lose out here.
Maybe it didn't sound the way it was type, but no they would still be joining a run in progress they just wouldn't know where the progress is.