It appears that the RSM will fire off hello commands as fast as possible in response to hellos that fail with ok: 0. According to the specification, it must only perform heartbeats at most every 500ms (i.e. minHeartbeatFrequencyMS), even if an immediate check is requested. We should update the RSM to respect this.

https://github.com/mongodb/specifications/blob/c3c82b62971f618e16e52ce04f9e13bb28f3ccd4/source/server-discovery-and-monitoring/server-monitoring.md#requesting-an-immediate-check