I think it's more about how the iOS app contacts the Stream. Right now it sounds like it's hard coded to use TiVo's proxy for out of home streaming. It might also just be a setup issue. They may be working on a UPNP method for setting up port forwarding, like Slingbox uses, so customers don't have to figure out how to do it manually. Honestly I don't know exactly. All I know is Margret mentioned that port forwarding wont work until the update in a couple months.
Developer for VideoReDo