I'm with both of you on that; the brake levers are junk. Because of that I left them off of my install, but another factor was that the bike I put the motor on has combination brake lever & thumb shifters, and I didn't want to have to swap out the whole works. The controller works fine without the levers attached.
After one ride, I don't see why a motor cutoff switch in the brake is even necessary. There's no such thing on any internal combustion motorized vehicle; you just naturally let off the throttle when slowing down.
Personally, if I had to have a motor cutoff switch, I'd rather rig a switch up that's activated by movement of the brake mechanism itself rather than the lever.