Edit: I understood your formulation a bit wrong, thinking that non polar pulls will take place after the basing stage, regardless of knowing the solubility issues of harmala alkaloids
In this case using lye to base up to the required PH at which dmt crashes, collect precipitate and further purify might work...
There is the possibility that more things will crash out from the chali ime. Drytek and stb without added defatting always yields an oily/resinous mess. It can be cleaned up but not sure it's worth it. I've had chali with 0.2% potency... not really worth extracting it in small batches. More of a brew admixture.
Also how would you test for the presence of each type of alkaloids in your end product to find out the procedure efficiency?