The single biggest challenge we deal with on larger projects is crawl budget limitation. Buried pages - pages with a depth over 10 often see little to no crawler traffic, which means that these pages tend to drop in value and expire over time.
Sitemaps are a good way of remedying this, as we could provide crawlers with direct links to the threads themselves, adding another avenue of discovery outside of organic crawl traffic.
However, the current sitemap layout only covers the first level of depth the site, which means the front page and high level categories. With depth we mean the number of clicks from the front page to the page in question. The RSS feed only covers a minor part of the site, and generally speaking pages that would have organically floated to the top anyway.
I think this is an issue that most users on this platform will run into sooner or later. While it is possible to alleviate this through third party generated sitemaps, they are costly and often cause additional strain on the property. It'd be much easier to generate these directly from the database.
One feature that could help with raising visibility for these buried pages would be a comprehensive sitemap specifically for threads. Currently you supply a category sitemap and a supplementary RSS feed containing the latest updated products. I'd propose a sitemap listing threads, including a lastmod field. Lastmod would correspond to the most recent edit or post to the thread in question.
The changefreq and priority field have little relevance for SEO at the moment and have been largely supplanted by lastmod, so I'd personally opt to leave those out.
Paginated pages (e.g. index2.html and beyond) don't necessarily need to be included in the sitemap, as that could potentially bloat the sitemaps to an unmanageable size.
This would also bring with it some unique challenges, as Google's limit on sitemap size is 50.000 entries in a single XML document, so would need to start iterating over the different docs. These can be delivered to google through a sitemap index.
sitemap-index.xml
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<sitemap>
<loc>https://community.insided.com/sitemap.xml</loc>
</sitemap>
<sitemap>
<loc>https://community.insided.com/sitemap-threads-1.xml</loc>
</sitemap>
<sitemap>
<loc>https://community.insided.com/sitemap-threads-2.xml</loc>
</sitemap>
<sitemap>
<loc>https://community.insided.com/sitemap-threads-3.xml</loc>
</sitemap>
</sitemapindex>
sitemap-threads-1.xml
<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<url>
<loc>https://community.insided.com/ideas/ability-to-search-through-members-database-in-the-front-end-2486</loc>
<lastmod>2021-12-01</lastmod>
</url>
<url>
<loc>https://community.insided.com/ideas/pull-unread-private-messages-to-top-4281</loc>
<lastmod>2021-11-30</lastmod>
</url>
<url>
<loc>https://community.insided.com/ideas/possibility-to-add-emoji-in-an-title-mostly-for-events-4293</loc>
<lastmod>2021-11-30</lastmod>
</url>
...
</urlset>
Sources:
https://developers.google.com/search/docs/advanced/sitemaps/build-sitemap
https://developers.google.com/search/docs/advanced/sitemaps/large-sitemaps
