I still don't think this is it. We used that to define a batch service, so I'm aware of that configuration.
One of our microservices is using the elasticsearch transport client, and rather than showing calls to elasticsearch, it shows that time as being spent in our process. we would like to specify the call to elasticsearch (unmontiored) as its own component in our service flow and timings
if you define the call to Elasticsearch as an entry point for a custom service it will be displayed and timed separately in the service flow.
You can then use tagging to mark all your external services if you like.