It is said that excess base causes the bark to further break down, releasing more alkaloids. I have put this to test and found out that adding excess base (lye) seems unnecessary.

On the first picture, you can see the exhausted shredded bark in water (left) and the combined-reduced-filtered water extracts (right).

An excess base has been added to the exhausted root bark until pH 13.0. This has been left to sit overnight and then alkaloids have been extracted.

The DMT yield (approx. 40 mg) from the exhausted and then chemically broken down bark (second picture) was very low showing that breaking down the finely shredded root bark using lye gives very little extra DMT, if any.

Can someone confirm this finding?

It really depends. But generally yield will be improved but depending on how well its shredded and the amount of base used.

Plant cells are build up with a big Vacuole (See attached image)
I imagine most dmt is saved up in those afterall they make up over 50% of plant cells depending on hydrations and also contain most non protein compounds and ionic compounds.

Now we know that cell membranes are made out of phospholipids. Lipdis already tells us everything.
Basic ions are able to disrupt that cell membrane. Basically "slashing" it open.
Now this would be more effective in live cells where the whole thing is still there.

Dehydrated plants cells usually already collaps and break down so there is probably not much use for extra lye in dried and grinded material. (see second image) Read here . Now ofc theres a difference in dehydrating a cell with saline or simply keeping water away but here it pretty much ends up doing the same.

But in the end more base as many postive effects like increasing density and thus pushing the dmt out more so I always recommend adding abit more if you can afford it..

My goal was not to save base but to get rid of the root bark so I can work with just the fluid in a separatory funnel and avoid emulsion problems (I get lots of emulsion whenever bark is present in the water or when too much base is added - saponification?).

I was thinking about filtering the tea after adding excess base, but the bark turns into a porridge that cannot be filtered plus I don't like the idea of filtering a highly basic liquid full of goop.

I was therefore curious how much DMT actually gets squeezed from the exhausted bark with excess base and it turned out the amount is very little if any. This is purely experimental result showing there is no need to break down bark with lye.

So now I just 1. filter the tea with simple sieve, 2. let the combined extracts settle, 3. decant next day (this removes the fine particles very well as they stick to the bottom of a pot), 4. filter through cotton, 5. reduce, 6. filter again with tightly packed cotton, 7. defat, 8. base, 9. pull...

Thanks for your useful information. I will bear that in mind when extracting from fresh plant/fungal material. So far I am just freeze-thawing the fresh material to lyse cells. MRHB comes shredded but I further grind it in a coffee grinder.

Processing acacia phyllodes prolly needs either drying and shredding or just blasting them with lye.

So far I was working with MHRB only.
I like any methods that don't include lye as I want to avoid goop in the liquid and emulsions. So the time saved by using lye is then taken by waiting for emulsion to resolve (and sometimes it won't as in my case).