Most consumers want their device to work right out of the box, mapping buttons isn’t something most of the population wants to deal with.
Don’t give them excuses, mate.
Map them during initial setup.
Please choose a service you would like to use and we will help you log in.
You have x buttons that are available to use as a shortcut to the service. Please press the button you would like to use, or press enter to skip this step.
But then you have to remember which one is which. The ones in your example are already labelled.
You work in their marketing department, don’t you?
The scenario I mentioned would have the buttons simply labeled with a number/letter. 95% of the time I don’t even look on the remote to use a button. Also, if you hit the wrong button, no big deal, you just the other/s.
Like I mentioned, stop giving them excuses.
Label the remappable button STREAMING SERVICE or something, I don’t know.