it's because of this why I feel anything like this occuring in mentor roulette (disconnect, leave, kick, vote abandon, etc) should lock you out of duty finder for the remainder of the timer left on the duty plus 30 minutes (or if it can't be scaled based on duty/time remaining, just a flat out 2.5 hour lockout). The idea is to make the penalty for leaving greater than the penalty for staying. And the reason I encompass all the ways, is to ensure mentors can't abuse things like dc kick to avoid the penalty. Yes, it will be abused by non-mentors who know that kicking a mentor will lock themn out for 2 and a half hours, but I feel that is the lesser of two evils here.
As for ex primals in the mentor roulette: Absolutely keep them in. I'd also argue for adding in Coils (except SCoB Savage, since there's a great story attached to Coils). Alexander and Omega normal modes are already in the roulette so no need to add Savage modes.