Probably not the hugest of priorities but it would be really cool if the Keystep Pro could be set to alternate tuning systems, such as >12TET, asymmetrical octaves, just intonation etc. I realize that the 12 tone layout of the keys might make it somewhat awkward to implement, but I think, at least I personally feel, it would be something I'd love to try playing with.
Just thinking of specific Max for Live devices I've seen, it shouldn't be too hard. One m4l device lets you tweak each of the 12(TET) tones individually, which apparently just works via pitch bend, so it seems like it shouldn't be all that difficult to integrate into the KSP.