It's interesting you mentioned the pull up of the SM2 with Tamiya masking tape, Eric (@eb801). And the overcoat with Tamiya acrylic clear to fix the issue. I ran into this same thing with AK Extreme metal, SM2, and Alclad II paints in recent builds. Tamiya clear does seem to work fine with all of these and I didn't notice any appreciable change in the metallic tone of the paints afterwards. I guess were still in that stage of metallic technologies where there's room for improvement. Still, I am glad we have access to these paints because most really do work quite well for the most part.
I am curious about the Vallejo primer 's effect you mentioned. I have always used Mr Surfacer 1500 in recent years and with very few exceptions, it has always resulted in smooth finishes. It has always been important to give the model a rub down after primer application.