Just to be sure, Odyssey (or pgBouncer) requires to run on the same box than Postgres, right? So if you are on AWS, you would have to migrate from RDS to running Postgres on a EC2 and install the pooler on the same EC2?

Which comes with some big drawbacks (you obviously lose all the benefits of using RDS) but also some benefits (can install every pg extension that you need, have access to every pg settings, etc)