I wrote one when fairly new to TW that turns out to be very similar to @springer’s approach.
https://talk.tiddlywiki.org/t/5879
A demo is at https://crosseye.github.io/TW5-demos/2023-01-13a/. Usage is very simple:
<<excerptList "[tag[Glossary]]">>
And it simply extracts the first paragraph from each matching tiddler, linking directly to the tiddler for more information.