I was just testing my game with my phone using the official Roku remote app, and it controls differently:
Tapping a direction works as expected.
But holding a direction has a long delay before the Roku gets the signal, for some reason (I'm assuming it's some sort of delay built into the phone app). If there's any sort of quick action in the game where holding a button is part of the gameplay (such as charging up for a more powerful shot/swing), this will cause problems.
Also, opening up the keyboard (in the app) and pressing letters and stuff sends unexpected signals (it crashed my game!). I've fixed this by more carefully coding what ids I'm expecting to receive and work with, but what if future changes in the app break my game?
But the question remains, for channel publication, does the channel/game need to pass testing with phone apps? I don't have any Apple product to test that app, for example.