I just spend ~30 minutes of over leveling the party so I don't need to do it later, and I thought I would use the 100 exp items to my advantage (they grant 100 exp to the entire party). I played until all the party members were there, then used all the items, and grinded exp with the full party present, so I ended up having the entire party a few levels above level 10. I ended up scrapping 2 runs to optimize this process (and to view more scenes). To my surprise when I changed classes for the story (which has a minimum requirement of being level 10)...
everyone's level resets to level 10.
So I've lost several levels for the entire party, and if I never used the 100 exp items grinding to just level 10, then I could use the items after the reset to achieve a higher level for the entire party compared to my now reset levels.
Time to bust out the ol reliable save editor