How to use FN keys as FN keys on macbook pro touchbar for ALL apps? Touchbar breaks my external keyboard, and the option to use all fn keys as fn keys is gone. Is there a way to do so anyway? For me the whole touchbar thing is completely useless, and I'd prefer only having it while I hold the fn key, like it works when I add a single app in the settings

Sierra 10.12, 2017 model
If you go to Settings > Keyboard, in the Keyboard pane, the box "Touch Bar shows" select "F1, F2, etc. Keys" as the option.

The touch bar will now just show Fn keys as if it was a normal keyboard. (They will dim and appear black sometimes.)

Then, you can change the setting directly below, "Press Fn key to" and select "Expand Control Strip" or "Show App Controls". This will fulfill your request to "only have it while I hold the fn key."

Hope this helps!