Maybe I am missing something,
but while I know how to select menu items for applications and the apple menu itself, I can’t see the way to do the same for menu status items like Stream Deck or BetterTouch itself-.
I would like to change stream deck profiles using its menu
unfortunately statusbar items don't have a common API like menubar menu items. This means apps are basically free to show whatever they want, making it impossible to have a standard trigger function.
You can click the menubar status items using the predefined action "Click Menu Bar Status Item", however from there you will need to use some other automation techniques (e.g. sending key strokes, using the find image & click actions or similar)