If you don't mind "just talking about this"
I would THINK (don't know) the adjust for in the car is clutch just off the carpet, then set brake to match. (think I have read where some racers set a stop so standing on the clutch doesn't break something)
So unless there is a documented "in the car" measured angle, setting on the bench is just good practice till in the car
some recomendations about pedal stagger would be good