Hiow long does it take to lvl from 91-100 in hyper swamp

[Congeniality]

genuinely curious, is mega maze worth it anymore?

Not even close, I did the math and Mega Maze is completely irrelevant with the crazy exp totals needed to level up as well as the monster exp orbs available from bosses (which drop more often now compared to when I tried). I would strongly advise that people stay out of Mega Maze for leveling to 100.