Just posting this here in case anyone else needs it later. I spent the better part of the afternoon trying to solve this problem and am happy to report I have a working solution:
Setup: Unifi Controller Running in a TrueScale App Container
Problem: Devices Cannot Access the Inform Host on the Usual Port 8080 Because the Port is Changed by the Container and Cannot be Below 9000
Solution: Use your FW to Port Forward 8080 to whatever container IP you are using for Web in TrueScale/Docker, BUT make sure you select the HTTP version and not the HTTPS version. Otherwise you will get a Server Reject warning.
If anyone has a better way of doing this happy to hear it but this worked well for me.