the alignment machines have the exact recommended value from BMW. there is an understandable +- tolerance range.
only toe can be set, camber cannot be adjusted for our cars.
unless you track your car, and only at the extreme, do you need to play with the settings. and by then you will need to purchase a camber kit. for all purposes, for all driving styles, just stick to manufacturer's settings will be optimum, for the camber, caster and toe.