Currently, the site details are only for the domain and not for subdomains.
e.g. for hacker news
The full domain: https://kagi.com/html/search?q=info%3Anews.ycombinator.com returns no result
When removing the subdomain, it returns a result: https://kagi.com/html/search?q=info%3Aycombinator.com
The same goes for help.kagi.com, chat.openai.com, etc... so it does not seem to be a special case with hacker news.
This means, if you hover over the ranking button on the search page, when a result is from a subdomain, there will not be any insights on that domain.
e.g. for news.ycombinator.com it only shows that this site uses HTTPS:
IIUC this would also affect the ranking, i.e. if site example.com has loads of trackers and stuff it would normally be down ranked, but if they just use sub.example.com they would not get down ranked as there are no statistics for it?
I expected to have domain insights for most of the popular sites/results.