This is a modification to #2 , which gates the logic on whether or not hot_standby_feedback is enabled. This article gives a good overview on what the feature does https://www.cybertec-postgresql.com/en/what-hot_standby_feedback-in-postgresql-really-does/ .

The only reliable way to run queries for >30seconds is to set hot_standby_feedback. This isn't turned on by default to prevent bloat on the primary, so we check for its presence before using pg_export_snapshot.

I refactored the logic to make it a bit easier to grok