Thanks a lot!
The REST API call did the job! :)
I got all APP AGENT instances.
Strange enough not all machine agents got in the report.
I have probably only a quarter of the total machine agents reported via REST.
Seems like the full list of applications I gathered does not contain some of the machine agents in the controller.
Could a machine agent be NOT part of a Appdynamics application object?
Shall I request another type of REST call for standalone machine agents somehow?