Nah, you treat them all the same. I have metallics that are straight lacquer and basecoat/clear, and I used to have them in straight acrylic enamel. I've had NON metallic paints of those paint types too. No difference in how you treat them. The metallic particles are in the paint (old-style straight lacquer), or UNDER the top layer of it (some lacquers, acrylic enamel and basecoat/clear). That's SLIGHTLY over-simplified, but not inaccurate.
There IS a difference in how some products LOOK on metallics, though. MANY people sorta prefer a synthetic-product look on metallics, that's one reason why SOME people prefer Pinnacle's Paste Glaz (which is misnamed, it's a wax, not a glaze) over Souveran for them.
The 1Z "Metallic" polish isn't really MADE DIFFERENTLY FOR metallic paints, it's just a name. They even put a disclaimer sticker on the can that says "great for NON metallic paints too!", or words to that effect.
