Yes, @ScoobyDoobie, I have used butane to extract MHRB. I saturated the powder with milk of magnesia (magnesium hydroxide in water), then dehydrated it at low temperature in an oven. I reground the material and packed the XPhase-50 (about 1oz sealed BHO extractor pipe system) loosely with fibers and powder to ensure liquid could flow. I sealed the system and froze it so I could easily fill it with butane through the upper check valve, then allowed it to warm to room temperature for an hour or so. Then I re-froze the unit to liquefy the butane once more, and expelled the liquid through the lower needle valve into a glass dish. The result was a small amount of yellow oil that smelled distinctly of DMT.
The main difficulty in this process will be flow, because bark powder is very fine. To do a larger amount of bark, I recommend a jacketed column on a heater/chiller, and making a parfait of powder & cotton layers in the column. Each layer should be about the same depth and the cotton should remain mostly uncompressed.
It is important to alkalinize the powder with aqueous base prior to extraction. You can use milk of magnesia as described above.
Cotton batting for quilting can be cut into discs and layered with the MHRB powder in the column. Fill the column with butane while chilled (just to -5°C), then close it off with some open headspace and allow it to warm up to no more than 30°C. Let sit for 1 hour, then chill again and drain through a cotton depth filter.