Some Substack-hosted /friends pages were failing verification because Substack blocks robot-looking requests. My checker now sends a browser-flavored request and retries politely on 429 and 403 errors. If your submission failed before, try again.
While I'm here, some detail on the crawler: it visits every listed site once a day to make sure the page is still live, pulls the title and a short excerpt for the directory card, decodes messy HTML entities, and notices when a /friends page links back here. Sites that link back get the FEATURED badge on the homepage.