#65905 is adding automatic configuration of heap size based on roles and memory available. This feature is the future for Elasticsearch; we hope to continue tweaking the auto sizing to further improve it. So we want users to use the auto heap, and we should add a warning when not using the auto heap.

This has one technical hurdle, which is the jvm options parser currently prints out the final jvm options on stdout, and we have no means to pass back such a warning to be emitted. We will need to consider how to split the streams and utilize stderr, or some other bash trick.