In regards to mao inhibition affecting the deacetylation to psilocin, i doubt its a contributing factor. Mao enzymes are completely different than deacetylase enzymes. But thats not to say it can't affect the pharmacological action of acetylpsilocin, with regards to rima maoi's from rue or caapi.
Though, mushrooms, 4-aco-dmt, and straight up dmt fumarate, when taken orally with harmala alkaloids, are all ayahuasca-esque, and from personal experience, have been some of the most fantastic/productive trips i've ever made.
They can get a bit bumpy at times, but one of my all time favorite psych combos, are extracted Caapi alkaloids or Caapi tea, and 4-aco, or extracted dmt fumarate. Its just something else.
Just start low, as it can get extremely intense if you don't account for the increased activity by the addition of a rima, theres a strong synergy/potentiation with harmala, and dmt and its alkaloid/synthetic 4-substituted/5-substituted cousins.
I took about 300mg of harmalas from a strong black caapi tea (extracted the same vine, so i kinda know the alkaloid concentration of the tea per gram of vine used), and 30m later, 25mg of 4-aco-dmt.
Probably the 2nd most intense trip i've ever had, only shadowed by my aya cherry popping with an unknown, eyeballed amount of freebase dmt (in retrospect, prob somewhere near 120-150mg), and 3.5g of rue ingested in gel caps 30m before the dmt.
In both cases, the visuals were unlike anything I've ever experienced before, and psychologically, not for the inexperienced/unprepared tripper. Though, usually the rough come up ends at the purge, or fades if you don't purge. In some ways, its easier after that point than if you were to just take some mushrooms, or acetylpsilocin. Harmalas are a highly underrated psychedelic in their own right, as well as combined with dmt, mushrooms, mescaline, or 4-aco-dmt. But i don't take it with anything but those psychs, and acetylpsilocin, only because in all likelihood its just a psilocin prodrug, like psilocybin.
I've even heard postive reports with bufotenine and 5-meo combined with harmalas, but i don't think thats for me after trying bufo and finding it repulsive.