The effects you get from smoking caapi arent necessarily from MAO inhibition, so when you're smoking caapi/harmalas you arent just looking to find the full MAO inhibition level. Harmalas can act on glutamate which might be related to potentiation.
Some people love smoking a big quantity, others find it too heavy and that it fogs the dmt experience.
Just make different batches and experiment and let us know what works best for you, there is no set way for everybody.