SWIM just did a test:

Evaporated 4 drops of his vinegar tincture to yield 20mg of Jimjam DMT freebase.
He then dissolved it in some warm IPA, it dissolved without issue.
The IPA is currently evaporating onto some mullein leaf.

This means that a super simple and quick method from extraction to changa would be:

Take non-polar solvent (Naptha, Heptane, D-limonene, Xylene, Toluene) and salt using vinegar.
Evaporate the vinegar until a red goo is yielded with no water left.
Dissolve the goo in IPA or Acetone (make sure to let the hot container cool!)

Now of course one could simply evaporate it all onto some herb, but that could be a lot of changa waiting to oxidize (maybe?)

in either case, the main question is: could one store the Jimjam freebase in the acetone or IPA and evaporate it batch-by-batch as needed?

Even if the answer is no, that's still a quick method from MHRB to solvent to changa, no precipitation, no excess fumeric acid, no freebasing with sodium carbonate...

There's no reason DMT shouldn't be stable in solution, assuming your solvent isn't going to oxidize it. Alcohols and ketones are, of course, not oxidizers of DMT. So acetone, ethanol, and IPA should be fine.

This could be a great way to measure out doses in someone who doesn't have a milligram scale. Put, say, 500mg in solution. Perhaps 10mL. Then each mL, assuming it's stirred thoroughly before removing it, should contain 50mg.

take spice... add to any high high proof ethanol. it dissolves.... this can be stored for very long periods of time. The "perfume" (old spice) can then be added to leaf and evaped at any point comfortable...