One alternative could be to add a separate column that can be used to keep track of insert order. But they would need to consider the costs before they do this, as it could impact the insert performance.
The true "modern" cool kids solution would of course be to create a service that listens to WAL, inserts it into a Kafka cluster that is connected to a pipe for inserting into Elastic search. Much more fun and resumé friendly than optimizing a query. I bet the author of this blog would get a much larger audience.
Bonus points if the ingestion service was written in Rust and run on a serverless platform
