Comment by cryptonector

Instead of LISTEN/NOTIFY you could listen to the wal / logical replication stream.

Or you could have a worker whose only job is to listen to the wal / logical replication stream and then NOTIFY. Being the only one to do so would not burden other transactions.

Or you could have a worker whose only job is to listen to the wal / logical replication stream and then publish on some non-PG pubsub system.