In the old days of flying 1/2A planes, I would color dope one day and fly the next. Maybe the dopes in the 60s were way more fuel proof than today's formulas.
HI John,
AS long as the dope dried, you would get a finish that resisted the burnt fuel getting on it. It is raw fuel that does the most damage.
Exhaust is mainly oil, the nitro is gone by then, which is what will mess up the paint.
BIG Bear
RNMM/AMM