I've a tendency to oversimplify things, like "enamels and oils use turpentine as thinner and acrylic uses water". It might have been true at one point, or in art class, it is not today. The Testors (both the small square bottles and the model-masters ones) worked fine with turpentine, just had a 24-hour drying period.

I know that today things are insane where some acrylics use acetone or lacquer thinners and some use water or alcohol. I'm thinking the wise thing to do is apply a gloss varnish before proceeding.

I thought I could cut a corner by using some old gloss white, I'm burning through XF2 like crazy, and the gloss surface would avoid the need for a varnish.