For R-wilds I would recommend maxing out R-cards that are available in gatcha since you will get r-wilds when you've maxed them out. The ones available in GHQ/explore will eventually get maxed and only give 700 pero so those wont matter as much.
As for SR I would max out whichever have the highest potential SED first which would most likely be Sexy cards.

Also in addition to Massume's point you can use the same tactic for Gambit (which is next I think) when opening the silver or gold caches to get SR cards.