(Tiger data employee fwiw)

We have an alternative full-text search extension as well, pg_textsearch that's completely open source that supports hybrid re-ranking

Here's a blog on it (i linked to the section on hybrid search, there's a code snippet for you in there)

https://www.tigerdata.com/blog/introducing-pg_textsearch-tru...

We're big fans of extending Postgres for more and more usecases