Hi there Achilles,
Is the caapi your using a form of vine or is it in some sort of extract? I dont have any experience with an extract but i believe ive seen it mentioned around here before, so i think its an actual thing. I think. In that case, im not sure what a typical doseage would be, sorry.
If your going to brewing vine, 2.5 to 3 grams wont be nearly enough. Depending on a few factors youll proly want to have at least 50 to 100g brewed, and possibly a bit more if you feel the need to redose or maybe if you purge too soon. Or just some other type of mishap. Because of the amount of time required to brewing, i always cook more than for just one session.
Just a couple suggestions though, but not totally necessary. Maybe have a couple sessions of working with the caapi only, get yourself familiar with the caapi your working with, and get a feel for where your sweet spot doseage is for you. I always like to do this everytime i cook a new vine or even with the same vine but just a new batch. Theres a lot that can be accomplished with caapi only tea or even rue tea or a harmala extract by itself.
Also, again not neccesary, but maybe start out with only one admixture. I only have experience with chakruna, so i cant suggest one or the other , but if your doubting your own tolerances for psychadelic experiences, its proly best to stick with one at first. Theres no shame in starting light in these experiences and working your way up to the levels you may be expecting from aya, theres no race. Peace