I really think that you shouldn't have any problems with metalizer over enamels or acrylics. You only need the thinnest of coats and the paint dries so fast that there isn't time for the metalizer to eat into the enamel or acrylic paints.
I've never had the metalizer eat any other paint, but then again, I've used it for years and I'm used to it. You really only need super thin coats to get full color from the metalizer range. You don't even need to thin it to spray.
If you REALLY dumped the metalizer on. I'd imagine the reducers in the metalizer would eat into the underlying coat.
I ALWAYS advocate the age old tactic of EXPERIMENTATION before you commit yourself to action that might result in a big mistake. Always test BEFORE you try it. It's easy - just paint any old thing with your enamel at the same time you are painting your bits for the model - then you have the SAME paint to test with. Get it?
Cheers,
LeeTree