Building a public UCP adoption census from published /.well-known/ucp profiles — directory? crawl etiquette?

[unblinkr]

Is there an existing directory or registry of published UCP profiles? I haven't found one in the org's repos or on ucp.dev.
Any crawl-etiquette preferences? We'll honor robots.txt, fetch each profile at most once daily with a clearly identified user agent, and follow the spec's fetch rules.

Context is I run Paddock (paddock.finance), an independent measurement layer for agent commerce. We publish daily-snapshot adoption and settlement data for observable payment rails (x402, MPP/Tempo). While UCP doesnt look to settle onchain I would still like to be able to publish information.

If a public adoption series is useful to the project, we're glad to make the aggregate series citable.