I want to thank stringreen for bringing this subject up and atmasphere's thoughts as well. I got off my duff and finally tried a material I've had around. It is a vinyl material, around 1/16" thick with a smooth side and an irregular other side. I cut it at 11& 3/4" diameter w/ a 1&1/2" center hole. (I left in place, my 1&1/4" vinyl based center donut). I'm using the smooth side down. With this arrangement, the center is slightly higher, so to allow some smoothing out of the lp when clamped.
It didn't take long to hear the positive effects after getting the VTA dialed in. I have the opposite experience of stringreen. No loss of air, detail. The bass is more fleshed out and powerful and much more musical. Music has more soul and is more enjoyable to listen to. A big upgrade!
It does kind of adhere to the lp when lifting one off. I don't notice any leeching, but I suspect if left for a long period, it could be an issue.
Next, I will try the carbon fiber alone and the CF adhered to a piece of this vinyl. For now, I'm just going to enjoy!