Create distinct indexes for Analytics nodes
To effectively use Workload Isolation, it is desirable to have different indexes on the operational cluster nodes than the indexes used to support analytics and reporting query patterns. It would be powerful for Atlas to enable different indexes on Analytics nodes.
The use of asymmetrical indexes across replicas in a cluster is not a supported configuration in modern versions of MongoDB.
Nevertheless it's certainly worth thinking about a future architecture that could support use cases with different workload and indexing requirements concurrently.