This is a very, very handy utility.
It takes a bit of getting used to setting it up and using it, but it's well worth the effort. It does exactly what I wanted; provides a flexible virtual controller that turns my MacBook's trackpad into an X/Y pad, a set of sliders, or a trigger pad that can be customized and configured to work with my DAW or other MIDI apps. I haven't explored using it as a mixer control yet. I like the use of the MacBook Touchbar for quick access to switching modes and transport controls; one of the few apps that justify using the Touchbar, in my experience.
Give it a try - there is a free trial demo which provides a full version of AudioSwift that can be used for 15 days.Read Review