Is it possible to toggle between two *custom* touchbars by holding the function key?

Hey everyone,

I know it is possible to hold function to disable BetterTouchTool and reveal the default system TouchBar when the key is being held. What I'd like to do is make it so that I can toggle between two different custom-designed TouchBar presets when holding the function key.

The specific implementation I'm looking for is that I have a custom designed preset that has music controls, sliders, and other widgets. But when I hold the fn key, I would love for it to display buttons for all the current desktops/spaces/full screen apps that I currently have open on the touch bar.

Essentially the default strip would be controls, and holding function would reveal an app switcher.

Is this possible?


FN is not possible because that's reserved by the system Touch Bar.

With other modifiers you could just assign them to the App Switcher widget (or any other Touch Bar item in BTT) like this: