Yes there is a separate grounding device available.
Goes between PSM156 and copper grounding rod.
I plan on buying one this Spring. Not pricey. Getting a copper rod into the ground in Minnesota right now would be a challenge.😊
I personally run a Datasat RA-2400 (2 x 400watt at 8 Ohms) through it, with a HDPlex 300watt linear power supply(for the server), my DAC, and a few low watt devices. No doubt you're aware there's individual filtering on each outlet, so nothing introduces noise back into anything else.
For the asking price of the SR PC SX I would certainly hope it performed better.
As far as power cables for the PSM156 goes I’m using the stock supplied cable but with Furutech NCF connectors which sounds fine. If I ever splurge I’d like to try the Hijiri Nagomi, but that’s a good chunk of change. Maybe Zavfino will be a future destination.