User is not informed about incorrect values in exposed-subsystems for MP Metrics

When I do stuff like

/subsystem=microprofile-metrics-smallrye/:write-attribute(name=exposed-subsystems, value=["batch_jberet"])

instead of

/subsystem=microprofile-metrics-smallrye/:write-attribute(name=exposed-subsystems, value=["batch-jberet"])

I get no warning about non-existing subsystem.

User should be informed about misconfiguration.

Question is when:

• when server boots
• when the cli / management command is invoked
• both cases