It's a Urethane, so it's safe to go over anything (So far I haven't had a bad reaction on any type of paint I've used it over!), and usually one to two coats is all you'll need. As far as hiding details, it lays down thin enough where as long as you don't go heavy, the details are still there. Here's a couple of examples....
The Ford script is still visible, and the side marker is still completely there, and was easily foiled...
I used Keith Marks decals, but the script is still there, so the added dimension gives them the look of real scripts!
A resin 428 hood for a '66 fairlane, you can see the chrome trim at the back of the bulges still, this is two coats of primer...
And the same hood, three color coats and two coats of U-POL, the trim is still there, and easily foiled!