As long as you are dealing with enamel over enamel, you should be fine. I've used Rustoleum primer from a rattle can under enamel finishes for spot repair and had no issues.
I do find, as mentioned above, that cure times for rattle can stuff is longer. Probably because they have to thin it so much to spray from a can.
Where you will run into issues is when you mix lacquer, enamel, or other types of finishes. Then you'll have problems with lifting and wrinkling of the substrate.
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