Sounds like a brake pedal sensor that cancels deployment with any input, if they're balancing a car already at speed they probably don't want the boost, but that's not energy wasted as it'll be available under acceleration out of the next slow corner, providing they're pointing and travelling the right way.

With energy regen, at first I thought nobody's going to be braking later and harder then they already do and that was it. But regen is active above 5 bar pressure of the front brake and some rear braking comes with the regen capture. To what degree does balancing the regen desire strategy with braking efficacy affect setting brake biases and then standard left footing, in reality and in heads? Maybe it's not so simple, maybe it's not worth the thought. In two weeks I'll find out.