The way the Harmony software/hardware setup usually works is that the hard buttons are used for generic functions, like volume control, channel selection, etc. The screen is used for component specific functions. In this case, phase invert, is the only component specific function either for your BP-25 or maybe a DAC used in your chain of components. If you wish to add more specific controls to the screen, you have to go back into the setup and do it manually. Google is your friend if you need help with that.