Over the weekend I read or heard that stability depends on every last point for grounding/dissipation. That's admittedly dubious but I don't know enough to dispute it. If I were supposed to use something more, it would have been included in the pack surely. Thanks for your input.
I would be very interested in reading that article. It makes little sense. Every mtg. bolt head is grounding the board's tiny grounding traces, as are every static 'finger' on the I/O plate at the back of the case, as is the ground wire from the PSU, and those are just the obvious places. Not to worry.