I've done several 1/2a models that way. And a few profile fuses. I like it

I am super slow ---finishing----except one time...another story

I have successfully sprayed Rattle can Enamels... several brands.... on a lot of different balsa/ply woods with various other coats of something

Adhesion and resistance to wrinkling seems to be greatly time dependent....
Example...Rustoleum over fresh 24hr dried dope n filler... while the ZS n dope was dry enough to be sanded away well...the thinner in the Rustoleum bubble/wrinkled the dope a LOT

BUT-----!!!  Same procedure with 2 weeks between Dope n filler sanded...Rustoleum went over the filled surface well...nice flat and glossy....happiness

I have never sprayed on top of dried Acrylic water colors....but I would think , IF fully dried...there is no problem....

NOW the 64$$$$$$$ question.... I would assume Rustoleum CLEAR over some Acrylic Water color....

We have basically decided that Rattle can clears are NOT fuel proof (with very few exceptions like Klass Kote or Diamond Finish Crystal Clear)

If this is an e-power I say no problem...BUT I KNOW for a fact Rustoleum brand clear is NOT FUEL PROOF

So I edit this in because Acrylic Water based paint did not really say...colored paint

I then think MinWax Polycrylic water based...DOH____YES! once dry--- the Enamel...no matter the brand,  lays down well and no issues I have experienced

Well I did it. So far so good.

And I agree the old spray valves are crap.