I guess it all depends on what you want the flaps for. If you need them to take off or land on a short TARMAC, I'd say use the dial, and use the 6 -> 2 mixing. If you need them for certain maneuvers, the switch would be the better option. Up, flaps up, center - cnter, and down flaps down. or, with your 8UAF, you could do both, and just use the one you need at the moment.