Ummm, yeah... the acorn video was essentially included for the purpose of illustrating how to precipitate tannins from aqueous ethanol. I'd put two and two together and made DMT, so to speak, as it was clear this could be applied to removing the tannins from a MHRB tincture while simultaneously converting the DMT to its freebase form. DMT freebase is very readily soluble in ethanol and aqueous ethanol down to vodka strength.

Re your question about adding sodium carbonate: yes this will cause a layer of more concentrated alcohol to separate along with the dissolved DMT, and this separation also occurs more readily with IPA than with ethanol. If you've already removed the red colour of tannins using lime, you should be able to evaporate off the IPA to collect a crude DMT goo. This may prove amenable to further purification using the FASA method. Indeed, if you were able to sequester any and all remaining water out of the de-tanninised solution, you might be able to crash the DMT out as the fumarate.

As far as extraction times go, it appears that following the protocol in the acorn video is effective enough. (And I hope Robert Murray-Smith appreciates the good use that has been made of his content  )

Finally, since we've been talking about removing water from the alcohol, it bears pointing out that the reaction of lime with tannin produces two molecules of water for every equivalent of lime, so if you're ever getting into the nitty-gritty of equations that needs to be taken into account.