This is an interesting idea as a possible stretch goal. I hadn't heard of it before either (and I can't promise to get to this anytime soon), but it would be interesting to try for those games that do not natively support force feedback effects.
Originally posted by @samuelgr in #8
Not sure if its done yet, but would be nice is any typical ASI\DLL hook\wrapper for any game could monitor game memory for events that could be used as FFD triggers, but to save devs of such mods a time for implementation of gamepad related features, it could use Xidi built in routine and just call it for enabling FFD effect at required strenght and for required time.