T. Spachianus has hordenine that is a MAOI-B. From what i have read it might activate a little of the dmt ingested from the psychotria but maybe not enough for a proper experience, cause the digestive tract has more of the MAO-A enzimes than MAO-b.
The information i found is old.. i wonder if some have now experiment with that somehow. Also, T. Bridgesii is said to have MAOI properties from its alkaloid makeup (bridgesigenin, kaempferol, quercetin). Anyone doing a experimental combo?