I run it on an ebike. It’s pretty awesome, but it eats range like no other.
All you have to do is set the “Field Weakening Current Max” to something like 10-50A and it will start adding additional current around 90% duty cycle to overcome the normal RPM limits.
The drawback is that it’s a fixed current. So with a 50A setting, 100% throttle above 90% duty will be 50A + whatever is needed for the actual load. There is also a concern that if the VESC faults while driving field weakening and that current stops, then the bemf voltage would be much higher and if that’s above the mosfets vds could short them and lock it up briefly… or something like that. I’ve never experienced it but it’s been discussed.
Some more testing here, and a few posts down: