Hi
My machine has the earth linked out to a connector on the panel.
The manual and video make a big fuss about grounding .
Basically thay want you to make your own earth point with a metal stake into the ground and use it to ground the machine.

1st of all, I'm asking "WHY?"

some thoughts also... it is looped to the mains wiring earth, so the new earth point will effectively be grounding the whole workshop and house wiring !

Could this cause any problems elsewhere on the ring supply ?

I haven't connected mine up yet.

For those old enough to remember .. it reminds me of going outside to pour a bucket of water on the earth stake, when the ground got dry, and the tv picture got smaller ! lol