your idea is interesting, but we should think about it twice before removing the devices you want to remove, as they have something this device can’t replace: the ability to be bound to a specific instrument: not every tracking command can be easily related to a single instreument
as long as the replacement-device retains all the functionality from the removed devices. for example, i often use the keytracking-device with both sliders set to zero in order to have something trigger for every note. i think this isn’t possible with the velocity-device (not 100% sure though). seeing how both devices have different parameters etc, i can imagine there being more of these situations.
Yes, I have realized a drawback is that gui would have to be slightly changed dependant on what you want to follow. But I think there are only very few parameters this would affect (e g note clamp in keytracking), so it might not be a big deal.