I hadn't tried it until you asked but yes, the results with the Soft & Safe fabric that I reported are the same, with or without the Earthing sheet underneath it.
The beauty of the DIY sheet is also that you can add connections to further decrease the resistivity of the fabric, which is already very low. Right now I just have one single pipe coupling connected to my ground wire, and i just wrapped a corner of the fabric around it and secured it with a rubber band. I imagine that if I were to add a contact at the opposite corner the same way, I could further reduce the voltage. The fabric's not cheap either, but at least you can use it anywhere in your home.
I used an 8ft copper grounding rod from Lowe's, 50 ft of 2 wire 12 gauge landscape wire also from Lowe's, which you can split if you want to run the wires to more than one location.