As a "in progress fisher" you do realise you contribute to waste the time of 23 other people, maybe take a moment and think about that.
A solution to this problem would be to add a 10-30min lockout upon multiple withdrawals from a ready DF que, either that or just hide the in progress(1/4 bosses down etc) display as suggested above.
Seperate ques would be a bad idea since it would just split the population up making for much logner DF ques.
This problem is the reason I just run one CT per week, with a 8person premade. Would probably run it more often if it didn't involve 10-20min of que ready popping up/withdrawn.