A few things:
1.) I do NOT think there's any blend of friction brakes taking place here. You can hear the motor whine as it regens all the way down to 0mph
2.) I tested regen and how it would behave on steep hill (going down it). The car regen'ed down to 0mph, and then automatically enabled "Hold." Now, if you press the brake at that point, it will take the car out of "Hold." I noticed on the regen bar that it was actually using a little energy to keep the car in place, NOT the friction brakes. After a few seconds of sitting with 0mph displayed, it went back into "Hold" mode.
Anyway, my feelings haven't changed so much on this new "Hold" mode. I love it for driving, - less so for parking.