Okay, so I’ve added outgoing Webmentions to Href.cool. This means that sites will be notified if they are linked in any of my category.
Incidentally, the directory itself has also has Webmentions. So, if you have an Indieweb blog and you want to recommend a link to the directory: make a post containing the link you want to submit and a link to the category page you think it belongs on and I will get the message. I may also choose to list submitted links at the bottom of the page. Or, yeah, you tell me if this is useful to you.