I've no direct experience but phenethylamines are generally not recommended with pharmaceutical MAOI's.
Be careful.

A dog smoked a caapi cigarette about halfway through a mesc experience and did not report much more than a headache.

Harmalas and pure mescaline are perfectly fine. This has been tested on numerous occasions.
I would not advise harmalas with T. Bridgesii, as even cacao mixed with this cactus has induced serotonin syndrome for some reason.
I would also not advise moclobemide with pure mescaline, or any of the cacti, esp. bridgesii.