Currently, all metrics are exported through JMX.

For VM and System metrics, it doesn't make sense, because they are already exported through standard JMX MBeans such as java.lang:Memory and java.lang:OperatingSystem

For historical metrics, it doesn't make sense to export them as typically the APM softwares (DataDog, Prometheus, Elasticsearch, Splunk, AppDynamics...) that will connect through JMX have their own time series database and will compute the historical data by themselves.