Hi Julian,

no Kunena generates links only for main threads and not for each single post. Thus if you have 10000 threads you will have 10000 links in the sitemap.

But take care, threads for the sitemap are limited by some constraints:
- Must be publicly accessible
- Must not be in the 'hold' state

About the number of links showed as indexed by Google, this is perfectly normal that the number reported is higher than links contained in the sitemap. Google Bot is able to crawl a lot of links on your site, even links that you wouldn't like to be indexed and even much more links of those contained in the sitemap of course.

You must rely on: number of thread in the forum -> number of links for each thread in the sitemap

Hope this explanation will be helpful, sorry if not!

All the best, John!