Excellent info ... yes I was planning to just taper off the paint to the outside body so it could be sanded down later .... and I think one of the painters here said when it came time to paint the outside you could tape off inside the doors but don't press the tape down ... so the outside coat fogs into the panel gaps ... then inside the jambs that fog can be wet sanded down later. .... or something like that
But then again ... when it comes to the outside paint ... the only places probably a real pain to do the trim would be hinge area, fenders where they show under the hood etc. There would be no sill plates, not trunk weather strip (or doors) no glass installed, stuff like that ... but would have fenders and hood bolted on ... I could remove valance and bumper for painting.
Good to know that it can stay in primer for a while, that was my worry.
I feel a plan forming in my head