How difficult and time-consuming would it be to add lastmod tags to the sitemap? To use them instead of priority and frequency tags. As far as I understand, this is quite difficult, because I only see a regular Unix timestamp in the database. And this timestamp only stores the creation time. What can you say about this?
These pages do have lastmod, but not the top sitemap.xml. https://community.nodebb.org/sitemap/topics.1.xml
Adding it at the top level would require looking at every topic to get the most recent lastmod.
save