This is yet another argument for putting regen on the brake pedal. If you ask to slow down (by pressing the brake pedal) the car could
slow you down in whatever way makes the most sense, using maximal available regen (which could be as little as none depending on
circumstances) and then using traditional friction braking for the remainder, such that the same amount of brake pedal force always
produced a predictable, consistent effect. There's just no way to achieve that via regen on the accelerator (unless you're willing to have
release of the go pedal actually apply the friction brakes, which seems pretty outlandish).