Most players will just want to farm the 50 Blue Souls and 55 Red Souls for the SSR weapon and eidolon. Returns diminish greatly after that. Don't burn too many BP consumables because you'll want to save some for Catastrophes. That's your ticket to easy SR assault weapons and Soul weapons, which can be an excellent power boost. Don't forget to farm the 15AP Disaster for your primary element 3x a day outside Advent events.
Yeah because 3k Jewel, 23 summon tick and 2 eye frags are "Returns diminish greatly"