mlbserver with roku?

I'm having trouble with the MLB.tv roku app so far this season. It gives a network error unless I watch the game from the beginning.

I found the advice here to use mlbserver, which I was able to do. It works great from my web browser. This page says mlbserver works with Roku Media App, but I am not able to get this to work. Is there a guide for getting Roku to find mlbserver? I don't see how to make mlbserver:9999 discoverable to Roku Media App.