[_paralyzed_]

I really don't think it's possible, especially on the motor side. It's possible you could rig something up on the non motor side, but then you're stuck with either front or rear brakes depending on how you position the motor.

You could spool the center diff and have both brakes (if you fabricate a cam) but that negates the attributes of the differential.

As far as the "feel" of esc brakes, atleast with a castle esc you can program them for any feel you like, and as long as you have good batteries you dont have to worry about braking killing the esc.(with a proper setup)

I hope I didn't disappoint you, but that's what I see.