Generic buttons rely on the board being able to utilise the "Automatic Indicator" in the button Control's settings. If this isn't the case, however, there's nothing that lets us use custom (or just more complex) indicators for generic stuff.
This can later be expanded to decide when the button illuminates. By default, the button will illuminate whenever it's assigned to something, but further control over this would be ace.
This should also show assignment details, such as which file will be run using "Run file" or which key combination will be pressed.