I have a 9x30 lathemaster that the first thing was to replace the spindle motor, I too used a KBRG225, I am using it in the 230v mode with a SEM DC servo motor with encoder and tach, on the 230v range, it is good for 180vdc motor and up to 3hp.
The tach I have hooked up to the KBRG for fine control.
I have 1:1 drive using a 1" timing belt and pulleys.
I replaced the 3/8 side plate that carried the reduction pulleys so I could make up a new C face mount for the motor.
With the inertia of the chuck, I get the OC led come on when accelerating and braking, it goes into current limit, but it does not falter.
Al.