Does your setup have spindle speed feedback into LinuxCNC?
If you have spindle speed into back into LinuxCNC then you can handle that with hal spindle-at-speed. If LinuxCNC does not know what the spindle speed is currently then a pause is a reasonable solution.
Just to point out a typo error: "G64 P.001 G.001" should be "G64 P.001 Q.001". You have it correct in your actual post-processor steps.
