I don’t think it should be easier, this underground can be done with adventure mons without any strategy. I think it should be more difficult. but i can only agree on it to take less time, hey 3hours/day is so huge guys, if you have a work/family/irl stuff this is literally not possible.
Since part 2 not released, just waiting for new ways to get xmas currency.
Just for information, 40hours = 400€ minimum, soo the choice is quickly done in terms of money.