I think 100 grams of good quality vine is a really good MAOI dose (the alkaloidal content is highly variable of course!) ... with that, for me, sometimes 80-100 mg of DMT is good for some not too intense inner work... but if you really want to fly, you have to go deeper and further... but even with 200 grams of vine...100mg is deep, but still, it won't take you out of this dimension... truly into the other dimensions... for that 150-200mg is what a lot of people need and even more.
What you also need to factor in, is that too much MAOI (especially rue or extract thereof) is generally quite uncomfortable... the good thing about the vine (more harmine usually than other beta carbolines), is that you can keep upping the dose and it just gets stronger and doesn't strain the system too much.
So I find it best to perhaps use more DMT sometimes and not try and totally max out the MAOI's the system... you'd have to do lots of trials using standardised extracts to really figure this one out with different people... and the most standard MAOI I use is harmaline extract from rue, which is, say, 50-70% pure they say! if you don't purfify it too much!
I use to work with 300mg as a standard harmaline dose for me, which would be a bit less than 200 mg harmine... but 350-500mg is what people with larger bodyweights and a typically quite toxic western lifestyle (compared to the amazonian version of purity!) do require.
Also, factor in that in the amazon, they go on diets when drinking a lot of ayahuasca. These MAOI's are there to break down toxins... when you go higher in your MAOI dose, you are opening your body up to being unprotected from a lot of these toxins.
In the amazon, when working with a vine a lot, people will go on a dieta, take no salt, sugar, no meat, no oils, no alcohol, no processed food and so on... they don't have a grip on the chemical aspect of this, but it makes sense you are taking a lot of vine, and experientially, very, very few people feel like having McDonalds and then taking a few shots of vodka the morning after doing a brew!
So I'd say to people, find your sweet spot with the MAOI's and take into account that larger doses may be toxic if you are are!, that harmaline can create more discomfort in higher doses as well.
The safest way to do this IMO is to get say 80-100mg of vine and say 40 grams of high quality chackruna or say 8 grams of mimosa hostlis root bark (a MUCH stiffer drink)... this is the traditional recipe... or you can use 100mg of vine and then bomb the Dmeech in cigarette paper 40 minutes after drinking the vine, this is a good way to understand how much DMT to use for one's system too.
This is in fact, my preferred way... most DMT containing plants taste pretty yucky when brewed up!
Julian.