Quote Originally Posted by Supersnow845 View Post
There is no reason to swap off your main during the MSQ till said main reaches the level cap
On the contrary, there is no reason to keep levelling your single job far beyond MSQ level unless you plan to never play a second job.

The alleged better armoury bonus is a myth (you simply get the same bonus rate for any job below your highest), and the only other potential benefit would be earning endgame tomes from roulettes and Khloe, but even that is only going to give value for a few weeks before you have a full wallet of tomes and nothing to spend it on until you reach endgame to unlock the vendor.

Additionally, quests and dungeons give a good chunk of EXP if you're doing them close to your job level, but relatively worthless if you're far overlevelled.

It's a much better idea to get a second class started and run roulettes with that.