JEE Application Monitoring - Tomcat Windows (as a Service)

Following the article here: http://www.buchatech.com/2013/04/monitor-tomcat-running-as-windows-services-with-scom/

As well as here: https://blogs.technet.microsoft.com/random_happy_dev_thoughts/2012/05/21/manually-discovering-jee-application-servers-with-scom-2012/

I'm able to successfully get BeanSpy installed, and run the script that configures the application, however when the application is visible in SCOM (2012 R2 UR12) it comes up with "The Health Service lost the connection to BeanSpy on port 443 to the machine"

The application is in an untrusted domain, behind a gateway server, and the management servers are unable to reach it.

Running something like:
.\New-JEEAppServer.ps1 -ManagementServer <gateway server name> -JEEAppServerType Tomcat -JEEAppServerVersion 8 -Targethttps://dunnyapp.contoso.com:443

Lands me the "Data Access Service is not running or is not initialized".

Running the same command, except either eliminating the -ManagementServer, or pointing it to any -ManagementServer with that DAS running, and communication fails.

So, this begs the question: Is APM for JEE applications *only available* if the JEE server is accessible from a management server on whatever port it is configured to use?

Thanks,

Scott