Whenever I do a low-level roulette, I do it on PLD, and I typically ask the group whether they want a fast run or a full clear. Most of the time, no one cares and we'll skip optional mobs and treasure (hey, I'm level 50 and don't need exp; if no one cares enough to speak up, who am I to argue?), but occasionally someone will prefer to get exp and I'm totally fine with that.

Honestly, when it comes to low-level Roulette, there's no value in rushing it. If you're level 50, there's much faster ways to get Tomestones (unless, maybe, you were gambling on a trial-size Primal and lost?). If you're under level 50, then the extra exp you get is worth a longer run. When I do low-level, it's pretty much just for a change of pace from the Brayflox grind, and when I do I try to be considerate of the folks I team up with. Leader of the group or not, a tank can't get very far without healer and dds!