compression is a holdover from old industrial controls. back when they could only process a few blocks a second. it wa sa way of optimising sloppy code from early cadcam systems. these days we can process hundreds if not thousands and even freebie cadcam software creates very clean code, so compression really should be OFF by default in linuxcnc.

ill also note that NOWHERE in the docs was there a reference to this being on if you dont explicitely type it. the only reason i ever found out was samco mentioning it off hand.