I have the GS20 already from previous machine. It’s been very good to date. I had 2 HYs that stopped working for no apparent reason decided it was well worth the extra $$ to get something that is geared a bit more toward true industrial use.
As for the ground I guess I’ve always been told that signal cable shields should be terminated on one end. I made probably close to 100 cables for Onefinity users for Masso to VFD and always terminated to VFD ground. Granted analog cables so probably not really required but this is just what I was always told for signal cables.