This is not an inexpensive hobby. Testing is not a waste of time. It is a valuable assist to our endevours.

In my opinion, if you cannot afford a bottle of dope for testing, you need to find another hobby.

Without testing, I'm just guessing, but I would say that you cannot put Aerogloss over Krylon. You may get away with putting it over lacquer, but I would suggest a test, first.