QUOTE: "I can see the 'edge' being an achilles heel. In fact... even if you spray painted your entire car in automotive paint... and later went back to touch up some paint chips with - the odds are high that the edges of the paint chip would curl up and wrinkle. I have had that happen to me 'back in the old days' when I used automotive spray paint to do touch ups on road chips in my paint." END QUOTE.

Definitely had this one with 2K paints. Went to touch up a 2mm chip in the bonnet with rattle primer the edges wrinkled and I had a 6cm patch to deal with as I had to apply the primer so thinly as not to unsettle the edge of the repair.

Another way around this would be to seal the chip first with some 2K clear but as you say this can eat the edges away as well.

One other way would be to seal the repair edge with water based clear as I understand this does not react with 2K solvent paints. Just a thought.