y0himba wrote:What exactly is the bitrate menu for?
Roku considers the bitrate screen to be an engineering tool, rather than a public feature. It can be of some use in testing, in that it allows overriding the box's automatic connection speed detection system to force a particular bitrate stream.
The playback debugging option displays the actual speed the box sees to the server and which stream it choose, as well as other information about the connection.
The screen was designed for use with Netflix and Amazon. It is less useful with other channels that may have only one or two streams. Netflix has 6 streams, Amazon 5 plus the 5.1 audio option.