Is there a way to get a list of more than the top 24 posters in a thread?

You can try this bookmarklet (AI-coded). Just drag it into your browser’s bookmarks bar and then click it inside the thread you’re interested about. It will load all the pages of that thread in a special lightweight format (JSON) and then show you all the participants and their posts.

Video of it in action:

https://fightingignorance.org/227a8854-f793-4be9-a80f-447e192d4ae7-discourse-participants-bookmarklet-view-all-topic-contributors-claude-april-06-06-23-54-pm.mp4