I'd stick with 5.5" on the V2. The factory 5.5" is good enough for MotoA guys and WSS guys to break lap records, so it's probably good for most track day folks. I mean, do what's fun, or I guess you're saying, convenient, and if it makes sense to have two sets, swap it up. But I doubt you'll run out of grip with a true track tire (180-190) on the 5.5" wheel. But yes, it will be less agile and feel a bit more "clunky" in corners. And it's bigger and heavier and will cost you some HP. And maybe calibration issues?
I run the MotoA Dunlop spec tires, which are 180/65 rear, and very tall, and relatively heavy. They changed the profile, shape and compounds last year, and it's much more like the Pirelli race tire. Though it's still a very still carcass. I'll post some track feedback when I get on it.