I’ve just reviewed the new post processor code and it’s a little better, but not perfect. They added a new option to control the output of the unsupported tool change gcode: “Output tool number” but unfortunately defaults to true when it should be false.
They did stop outputting the unsupported “%” lines which is an improvement.
The last issue is that they still output M30 to stop the spindle at the end of a carve. With recent versions of GRBL this is technically correct and will work but wasn’t supported until recently so some Gcode senders (Like UGS) filter it out as a workaround. This means that your spindle will not automatically shut off at the end of a carve. I had suggested they use M5 instead while will work and not be filtered out. Since this M30 code is now supported the real right thing to do would be for UGS (and any other sender) to stop filtering it out when a newer version of GRBL is detected, but that’s going to cause confusion.