I truly appreciate your diligence and that you have perhaps stumbled upon something with promise.
The cork surface is similar to a cork-rubber surfaced also manufactured by the Regupol people. I rejected it because it looked really, really uggggly and was quite expensive per sq yd. You could paint it, but that would ruin the traction or at the very least, be impractical.
The other stuff (Cerazorb) does look interesting. It's a little on the heavy side, but not nearly so heavy as 3mm rubber. And from my testing of rubber, 3mm is the ideal thickness (2mm holds the contour of the surface underneath too much, i.e. tile joints and thus lies uneven, 4mm is too heavy)
There are three criteria it must pass to be better then what I'm using now (said smuggly after searching a year for the best surface
1) It must deploy flat when continually unrolled/rerolled/unrolled (some rubber does, but lighter/intermixed stuff tends not to). This is a biggie for a convenient, roll-up portable track.
2) It must not have too much traction so as to cause traction rolling with the cars or excessive rear-end shudder (without a fancy, scmancy damper). A stock d'NaNo must be able to run on it well without excessive tunning, with the exception of the correct tire matching.
3) It must be reasonably easy to cut or shape with hand tools. (it's difficult to make a true, straight cut on 3mm rubber)
It is already the right color, thickness and width (although 6ft wide would be better) —a good starting point a worth testing. The lighter weight (when comapred to rubber) also suggests that it might be easier to work with.
I'm going to contact the manufacturer and see if I can get some sent up here. Ya' never know, it just might be good. Now if you can only attract another 5,000 people to the d'Nano class, I might be able to explain to the company President (my wife) that there really is a market for these tracks ...