A higher difficulty roulette might work. I'm not sure if I'd want to see randomized modifiers. The roulette might be at a fixed difficulty and the modifiers could be edited for unrestricted party. People do run MINE or atypical party compositions for fun so I can see the modifiers being used.
Sync in combination with roulette is really bad for learning jobs. As you go higher and higher, it becomes less likely that even get to use your latest skills and you have to be ready for 10-20 different playstyles at random depending on how you get synced.