Yes, and yes...
Sublingual and/or oral MAOI before vaped DMT or Changa can have profound positive impact on the initial smoked experience...
One can also make harmala saturated herbs, without DMT... Dissolving excess Harmala into the solvent, then mixing herbs and evaporating. With excess harmala, some powder will be left after evaporation, but the herbs will be maximum super-saturated, coated with harmala freebase crystals, sparkly like cannabis.
These herbs can be smoked before smoking DMT-containing Changa or DMT... To load the body up on harmalas...
Alternatively, one can take these max-saturated Harmala herbs and roll them in red full spectrum DMT goo freebase, then do a final roll in the residual harmala powder... Makes kind of a Changa moon-rock... Maximum harmala, rolled in DMT goo, coated in even more harmala (helps prevent it from being too sticky from the DMT goo).
It definitely works on the first smoke moreso than just dabbing the DMT goo... but you are right, in that subsequent rounds will be stronger due to the harmala taking effect in the body.
-Eternally Romping the Astral Savannahlands-