Isn't the regen level independent of which mode you're in? The way I understand it, when you use the left paddle to increase the regen, it sticks in SPORT Mode, unlike the way it shortly resets back to the lowest level of regen in ECON and NORMAL Modes.
Interestingly, while the regen level sticks in SPORT Mode, the Clarity won't stick in SPORT Mode after you power the car down. I don't see that as a big problem, but I sure wish the car would stick in HV mode if you leave it in that mode when you power the car down.