For some reason I didn't realize that running the Smoothieboard via ethernet was significantly slower in transmitting commands vs USB serial. I'm not sure exactly where the bottleneck was, but it probably had something to do with my router. Switching to USB made a significant improvement in speed, especially with anything related to vision.
Recently I also printed some new tape peelers for the existing auto feeders while making some new ones. These peelers were published here. I used sg90 servos, but gutted them so they are just motors. I'm sure I could've figured out how to use them or mg90 servos, but it was easier to just modify off brand sg90's, and cheaper than buying new faster n20 motors.
With these two modifications, the machine is now up to 1200 parts per hour with bottom vision off for 0603 parts. Accuracy is pretty good, but still needs some fine tuning. The recently added runout calibration to OpenPnp helps too!