I'm trying my hand at this

One piece of the tek concerns and/or intrigues me though.[Emphasis added]

If the NMT were in the NP as the freebase alkaloid, recovering the solvent by distillation would probably work since NMT is high boiling and amines rarely form azeotropes.

Amides do form azeotropes. For instance, if you add the high boiling compounds acetamide or dimethylacetamide to xylene the mixture will distill over at a lower temperature than either the amide or the xylene boils at. Wont acetylNMT form an azeotrope with some/most of the solvents we are using and distil over with the solvent before the pure solvent distills over?

This could be a novel way to purify acetylNMT, assuming the azeotrope forms and contains significantly more than 0.1% acetylNMT. It could also complicate recycling of solvent unless you had a good fractional distillation setup and could see an unequivocal temperature spike when the acetylNMT azeotrope finished distilling over.

Since I dont have a GC/MS at hand any more I think I'll just try to hydrolyze the acetylNMT back to NMT by refluxing with 1M H2SO4 (aq).