When I built the new wood track, I rolled two coats of gray latex gloss paint on it. Nice and smooth like I wanted, but all the imperfections in my work jumped right out. So I put a coat of flat finish on it, but with silicones it didn't have the traction I wanted or I had with my last wood tracks. I figured to try some other paints and see what worked best. I tried flat epoxy, spray rustoleum with some kind of grit in it, a coat of clear polyurethne, a coat of the gray with some aluminum oxide (from my bead blast cabinet) in the paint and a coat of gloss latex gray. I then put a car on each type of paint and angled the track piece till the car started to slide. The clear coat and the gloss latex were the best, so I brushed a coat of gloss gray over the flat. Now traction is fine and brushing seemed to not highlight the un-eveness in the wood.
With urethane tires, I think it would have rubbered in, not sure the silicone would have.
Here is the scientific testing.