I setup AX 2009 SP1 with EP.
EP works great locally using http://epserver01/sites/DynamicsAX
However, i set up also an External URL for EP like https://www.companyabc.com/sites/DynamicsAX and it partially works.
All the web parts that display SSRS don’t function because they try to connect to SSRS with http://epserver01/ReportServer
I’ve setup an external url for SSRS using SSRS Configuration Manager and it works. However, i am not able to configure EP so it uses SSRS external URL when invoked externally.