This is another item that will have to wait for 2.X. Not all functions in 1.X can be controlled by a trigger, but I'm going to change this in 2.X. This will allow for complete custom UI skins/interfaces as well as control of just about anything with a keyboard. I even plan to add "modes" so controllers/keyboards can have different mappings for different modes.
In the meantime, please check out this addon:
https://hub.virtamate.com/resources/keyboard-shortcuts.281/