I am doing a Marsofold A/B extraction with 1/4lb MHRB. Just as I finished basifying the solution
to pH 13 with NaOH, a family member who wouldn't be too thrilled to discover my chemistry
experiment arrived. Consequently, I had to conceal my solution-filled jug in a closet. I will not
be able to resume the extraction process for 24hrs.

I am no chemist, so I thought I might be able to get some advice from more knowledgeable and
experienced heads. It seems to me that a 24-hour bath at such a high pH would be damaging to the
DMT. I have no real understanding of what might happen to the solution if it remained at such a pH
for a very long time - so, do you think it will survive the 24 hours at pH 13?
Or will I just have to abort this extraction?

DMT is stable in basic solution for quite some time. Nothing to worry about.

a lot of people do a pull over night..

My last extraction was sitting for over two weeks before I pulled, and it is still sitting there now waiting for a final small pull which I probably wont do for another couple of weeks (or longer if the xylene remains clear). I dont understand the chemistry of it but high ph doesnt damage it. My laymans understanding is that it is because dmt is an alkaloid and has a high pka, making it stable in highly alkaline solution?

It's fine, don't worry about it. It would be perfectly fine for weeks, if not beneficial, giving the cell structures more time to break up. The alkaloids we work with are perfectly stable and unreactive to acids and bases. When you start adding other chemicals that would act as a catalyst, then things might happen.