Mitchell <mitchellahren@gmail.com> writes:

>> If you remove all the non-ASCII characters from the Org file, does the
>> slowdown go away?
>
> Eli, that solved it! The new test file is at
> https://gist.github.com/kings2u/2ef0e145f2b42d0a13605b0dc9b6e6e2. I
> replaced every non-ASCII character with an "a" so the file still has the
> same number of total characters, and in my emacs 30.0 50 build (as of
> 2024-05-25), doing Steps 1 to Step 7 gives me abbrev expansions that are as
> lighting fast as in emacs 28.2!

Hmm. Then, does the attached patch help?