hi, wondering which would be the most volume efficient tech in terms of aciid/basic soups amount of solvent, etc? working with less volume would be the goal. thanks

I think you can just pick any tech and then just use as little as possible.
Usually water is no problem for using (expect having a way to store the base soup)

What i liked to do to save solvent is simply making a pull with naptha.
Freeze it and then just pour off the naptha back into the base soup.
Then just let it dry. Scrape of the dmt and redo.

DRY tek Q21Q21? so dense you can fit more than you need in a bucket ?

Probably any STB and A/B tek without salt can use less volume of water.

When working with 100 or 250g MHRB, I would not go under say 700 or 1 200 ml water respectively. I once tried to concentrate the tea too much and it clumped just from adding hot salted walter (salt tek) and from adding base. It clumped because the alkaloids were too concentrated.

2L container is enough to hold the basic soup.