We are planning to tear down the legacy search.bsky.social service immanently. As noted in #26, that index has not been getting updates for about a week.
This migration was hinted at a while back (bluesky-social/atproto#1711), and there is a migration path to switching over to specified search endpoints on the appview (api.bsky.app). The cached public version of the appview (public.api.bsky.app) would probably be a good fit for this use case. It might require tweaks to reduce the query/refresh rate to stay within rate-limits, but a lot more hydrated metadata is now returned by the endpoint.
I think @jcsalterego has been pinged about this recently, but commenting here for visibility.