Allan,
Back in the days when dependable AeroGloss dope was available, it seemed to be simpler...
A wet wipe-down with A-G thinner both removed any mold release agent, AND, perhaps, micro-etched the surface for decent adhesion with A-G colors and top-coat clear. (Same worked for color doping clear $kote, btw, but adhesion was marginal. Masking tended to lift the underlying coat, yet if done right, could last beyond the expected finish.)
Note: This Monokote Clear, scuffed, finish was about the lightest that could be done! Given: the plastic film added near zero stuctural strengh to the bare bones. BENEFIT: IF the wood under the film was sanded and tack-cloth-ed well enough, the finish compared well with the slow, smelly and iffy buildup of dope/sealer/sanding/dope/sanding/tack-ing/ clear sealing/color doping/ detailing/ top-coating sequence we had been doing for the 25 tears before.
Alas, butyrate shrinks too much, too quickly, for the dope over (micro-etched) film....
And, to day the EPA (Enjoyment Prevention Agency) has issued too many 'Thou shalt Nots...' to prevent us using anything that works, if we are to enjoy the results of our efforts. (NOTE Len - this is not political: it has broadened its impact to all of us!)