We just got a GR-510 at my work. The biggest issues I am running into using the "GENERIC HAAS 3X MILL" Post Processor is with the tool changes. The tool change height is at Machine Z=0. But the spindle can additionally travel Z=4.538 above this position. Most of the time, I have to command a " G0 G90 G53 Z4.538" following any "T# M6" to avoid crashing the tool before any X or Y moves are commanded.