Hi Michael, and welcome to the community!
Ahhh… the search engine. Have you considered an inverted search index? It’s been my experience that the moment you place Airtable in between the user and the data, things slow down a lot.
This can certainly work, and latency wouldn’t be an issue if the external database were fast enough to return the results. In practice, this is a challenge and why I lean on an inverted index which can return results in milliseconds even on a very large data set.
Here’s a paper I wrote about this topic some time ago.