I finally tried the 80A controller but, disappointingly, it didn't work.
I tested each hall sensor using a voltmeter and all three are good. The voltage reading changed from 0-5V when I turned the motor by hand.
I tried all 36 phase and hall wire combinations but none of the combinations turned the motor. The amp meter shows current kicking in, with the needle going past 50A max reading if I opened the throttle wide. But the motor just jolts and locks and doesn't really spin. Any ideas on what else I should try?
Here's a bit more info on the controller: