Have you ever considered using PGroonga (https://pgroonga.github.io/) to further extend FTS in postgres? They've got a drilldown feature that is basically their implementation of facets. Always wondered what your thoughts on that might be?

I've got a django setup with postgres and facets implemented as you detailed in your blog (thank you for all the amazing info over the years btw!), now I'm looking to extend it with PGroonga and potentially considering Hasura to try and further extend what I can do while still using Postgres as my single source of truth without need for keeping any other service in sync.