Just an idea. 99% of SK players now farm FSC every single day, but what would happen if every other Stratum 6 had the same payout as FSC? Maybe even slightly more payout than FSC, as FSC's D28 is the throne room boss fight and logically should have less payout than any other D28.
EDIT: I'd like to add that arenas should be the only exception to this payout rule, just to give people reason to play through them instead of choosing to constantly farm easier levels.
Note: this is not a suggestion, I am merely bringing up a hypothetical situation for people to discuss.
Then people would farm whatever was easiest/had the fewest enemies/was quickest.