Well, I bit the bullet and tried Future sans a black background coat. I used a Hassegawa P 51D (newer mold) , which has no fit problems, as my test subject. Prior to Futureing, I polished everything out with Novus #2 and then used Windex to clean off the residue. I then went with Future, a couple of light coats, and then set it aside to cure for 72 hours before using Alclad 2 aluminum. I compared the results with a test kit where I had used Krylon gloss black as the background color and the finish looks the same. Perhaps on a larger scale model one might be able to see a difference. In any case, I highly recommend going with a Future base for the regular Alclad shades. The only downside, that I can see, is the Future cure time.
Mike McShea