Hi Bill, thanks for your reply.
I've tried the first option you described, I have two conditions MotorOff (zero throttle curve) & MotorOn (normal throttle curve) controlled by a rotary dial LD with wide hysteresis to make it unlikely to accidently alter this in flight.
Trying to get my head around the second option you described (...OR you can use a dual rate set to zero flat across throttle curve, etc ). If I managed to set this up .... would it mimic the way the T6K's ESC throttle cut works ?