To me, there already exists a way to poke a hole through SR - Conjuration spells. I'd rather see lower SR's, than spells to counterbalance, because I'm just philosophicall opposed to the whole "counter-escalation thing" that pervaded 3E.
generally I don't ever get around to playing at the sorts of levels where this even comes into effect. However I've been running reverse dungeon for my players and I had to learn how to play high level very quickly. I really had problems because I wanted to fight the pc's (who were Monsters) but not outright kill them. I found this to be very hard to pull off this balance it just seems to be when you get to high level who fails their save first. Note I didn't set out to find this out, I didn't go looking for this problem, I wasn't out to get the system. I just found it very tricky to make it challenging without being outright lethal :\