Very interesting writeup OP!! This sounds like something definitely worth trying!!
Massive improvements to vacuum operations:
"PostgreSQL 17 introduces a new internal memory structure for vacuum that consumes up to 20x less memory."
Much needed features for backups: "pg_basebackup, the backup utility included in PostgreSQL, now supports incremental backups and adds the pg_combinebackup utility to reconstruct a full backup"
I'm a huge fan of FDW's and think they are an untapped-gem in Postgres, so I love seeing these improvements: "The PostgreSQL foreign data wrapper (postgres_fdw), used to execute queries on remote PostgreSQL instances, can now push EXISTS and IN subqueries to the remote server for more efficient processing."