"The first part of the MSQ" is pretty vague. How far in the MSQ starting at 50 did you go? Did you just finish *spoilers*ultima*spoilers* or have you advanced beyond that.

There's a LOT of post-50 MSQs to do, and you should do every dungeon once so you have access to roulettes. You will be forced to do some of the dungeons to advance the MSQ, so you can do the MSQ first before slogging through the dungeons.