you don't really have to adjust the prim and sec blades so that the transfer is exposed the same amount for each.
the baseplate might have a shorter transfer slot on the secondary side. One way to do it adjust them evenly and expect the secondary side to be hidden or just on the verge of peeking past the blade.
I usually adjust the front to roughly .020 exposed on the transfer slot and then adjust the rear to show about the same area of light showing as the primary side if i hold the carb up to some light and look up through the venturis from the baseplate side...
a good starting point at least.
from there roughly adjsut the prim and sec sides evenly to get your idle speed.