Enable Query Store for collection on a read-only replica in an Availability Group
Currently, Query Store can only be enabled for the read-write database in Availability Group. As many customers issue queries against the read-only replicas, capturing query and performance metrics for those queries would be beneficial for understanding the workload, troubleshooting performance issues, etc.
Alex Friedman commented
This will be invaluable for us, and assist us in growing and directing more traffic to secondary replicas. Please give it priority.