Another way to remove tanins is to add a bit of gelatin to the brew, which binds to the tannins somehow and forms a dark brown goo that grabs a lot of fine particles on the way down. Make sure though that either you don't want to reuse the container you do this in, or that it has easy access to scrape this crud off because it is a royal pain to clean once it sticks to something. I ended up throwing out some canning jars after doing this as it was not worth it to try to get the stuff off after the fact. I can imagine that once this gum like stuff dries it might be easier to scrape off, but at the time I just didn't want to deal with it. There is also another product called polyclar which is used in homebrewing to remove polyphenols (such as tannins) from the final beer/wine just before bottling. This should work too, but I'm not sure how it compares to gelatin for this aside from the fact that polyclar is not soluble in water. This means that if you use an excessive amount of polyclar it would not dissolve in the brew, whereas gelatin would. To reduce the mechanical loss of dmt due to decanting it may be best to remove tanins before reducing the volume of the fluid.
On another note, traditional ayahuasca brews are generally one pot conglomerates of a variety of plants. I think the process of collecting the ingredients is much more involved (asking the spirits of the plants permission to harvest, etc.). If you wanted to do a one pot extraction, and something is likely to take longer to extract than something else (root bark vs leaves), then doesn't it seem like one might just add the ingredients at different times in the boil? Overall, I think it is mostly a matter of preference in the long run. One advantage of doing seperate extractions, however, is that you can get to know the properties of each plant and the brew thereof.
A shaman will tell you that the plants are teachers (or the spirits of plants). The formulation and preparation of ayahuasca brews are traditions based on many generations of beliefs and observations regarding the nature and how it relates to the cultures of those that prepare them. Ayahuasca is a sacrament of the highest order and traditional preparation is more akin to alchemy than chemistry. There are perhaps inefficiencies in their preparations from a chemist's point of view, but if you were to have a chemist prepare a concotion based on an assay of "active ingredients" in a traditional brew and try to duplicate it you would still have a different product (albeit still very active). It would be interesting to compare a chemist's duplicate 'huasca to a traditional brew it is meant to emulate in a traditional ayahuasca ceremony, but I digress this is spiraling farther and farther from topic.
Anyways, if it was me, I would extract everything seperately and combine all of the extracts just before reducing the volume. I would likely remove tannins before boiling the extract down, but it's not really a requirement. I've had mimosa hostilis extract with and without tannins and still got the purge either way, but without the tannins it was less bitter and easier to drink.
