I've loving wide tires. I've modded my CVT bike to run some of those new, road plus tires from WTB. The Byways. 47mm wide. They are wonderful on gravel and double-track, and on potholes.

Were I implementing a CVT shifter on drop bars, I think I'd consider some sort of left- and right-hand trigger system in which the left and right triggers opposed each other, pulled opposite cables to the hub, and maybe squeeze left to increase resistance, and right to decrease it. Something like that. Maybe.