Just to check you are using the remote and not the app on a phone, the app does not do press and hold, “ramping” as you call it. If it is not working in Devises Mode it has nothing to do with the Long Press Feature as that only works in Activities. Did you try the AVR-S670H code base (I know you have a S570BT but it should work)? When you press and hold the volume button does the green light on the hub flash continuously or just once? And as an explanation the “Long Press Feature” allows each button to have 2 functions in Activities. So my 3 bars button in the PVR Activity is Short Press for Guide and Long Press for Recordings List and it can be for any devise in the Activity so my Short Press of Mute mute’s the Denon and Long Press of Mute cycles the TV Picture Modes. When this feature is used the button loses Press and Hold (ramping) functionality so is best not used on Volume and the Direction Arrows. And don’t worry “ramping” does work on the remote so it’s just a case of working out why yours isn’t.