I want to open the last group opened

it will be cool to open the Touch Bar group I opened just before, BTT should do this in an update

I like the idea, note that with a bit of applescript, this is already possible now.
(each time you have a trigger opening a touch bar group you add an applescript running setting
a string variable to tne name of the touch bar group.
Thanks to that you can easily create the trigger opening the last open touchbar group

Cheers,

Olivier