Coasting, B or other?

As I understand it, using B going downhill in HV mode spins the engine. In EV mode, B uses more aggressive regeneration (until the battery is full), and is equivalent to lightly pressing the brake pedal.

 

When in EV Mode, "B" makes the Prime drive more like an all electric vehicle (or at least more like the BMW i3, which I test drove). With the i3 you could theoretically drive completely with the accelerator pedal and never touch the brake pedal except in an emergency. Pushing the pedal down speeds you up, letting up on the pedal slows you down. With the Prime in "B" it runs more like this. This feels very different from what we are all used to, which is when you let up on the gas you "coast" and/or the car gradually slows, or maintains your speed when going down hill. To me it's just another way to drive an EV, but one that takes some getting used to. Not sure yet which I prefer. It doesn't seem that one is inherently more efficient than the other. I assume that the goal is to never use the friction brakes, ever, and I think you can do that in "D" or "B" with careful driving. I've been assuming that the way you know you are not using the friction brakes is to make sure the blue braking bar on the display never hits the bottom. Does anyone know if that is true?