The most convenient answer would be to just get the SR 1s over EX still...getting a ton of EX Wilds takes a lot of time to process with Kurito (2 HR timer sometimes) and honestly some of the rewards really are not great. In fact I would say I don't normally get an SR3/5, I usually get pudding. Worst results for EX Wilds would actually be a single half pudding, the limited cards once you already have it, or the PeroGlasses, and the first two happen quite a bit. Although in the long game it's very good for a mostly f2p to trade in EX Wilds for puddings, especially since pudding can be traded in again anyway for a good shot an SR3 if you don't want pudding. EX wilds won't increase your SED much in the short term if that's what your looking for, that's a choice you'll have to make. EX wilds also can't be used at all until a card is at 100 and you've finished some of the "one time only" missions. And there's nothing special about the tradable cards other than they're going away soon.

Lol the more I'm thinking about it the more convoluted it gets...especially since there's a lot of hard data still lacking on Kurito and trading in EX Wilds. But again, for short-term SED, EX Wilds aren't a good choice.