Currently it is only possible to disable BetterTouchTools while holding a key combination. I would like to have the possibility to toggle on or off BetterTouchTools by pressing a key combination once.
Reason for it is to have the possibility to switch contexts once for the touchbar (I like to use the touchbar as a "global" system setting but sometimes i would like to have the option to use default application specific controls)
For this you can use the predefined action "Toggle BetterTouchTool Touch Bar"
While it is possible to use the predefined action, once pressed, I am back using the default touch bar where there is no possibility to press a button on the touch bar to switch back to BetterTouchTools unless a modifier key is pressed. I'd rather have a key combination to easily switch between them. (Or use the current option while holding down modifier keys)
Why not assign the predefined action to a keyboard shortcut?
As far as I understand the keyboard shortcut requires a non-modifier key, which might trigger a shortcut in an application.
I have to admit this feature request is a bit nit-picky.
Key combinations on macOS always require a non-modifier key, but you could use the key sequences feature in BTT which allows to use any sequence of keys (however it does not block them)
I've setup the key sequence as followed in 3.560 (1700) alpha. I am only able to disable. Once it is disabled, it cannot be toggled via keyboard shortcut and I have to open BTT to make it visible again. (I have unchecked all checkboxes in Advanced Settings > General > "Disable BetterTouchTool while holding:")

Creating a shortcut via Key Sequences and using "Toggle BetterTouchTool Touch Bar" action solved it.
It requires a quick succession of inputs to toggle between them. I was holding them down.
Thank you @Andreas_Hegenberg for your quick replies and help. I love the program!