Nice - how can this be adapted for hosted Postgres' not using Neon?

You can replace the @neondatabase/serverless module with the node Postgres module (pg). Here's a sample of what that would look like: https://github.com/subzerocloud/showcase/blob/main/vercel-po...

What about the HTTP sunset header? https://datatracker.ietf.org/doc/html/rfc8594

This is pretty thorough - but misses the HTTP sunset header

Author here - I actually plan on covering the deprecation header in a different post on sunsetting

Cool!