i fly all my planes with a flaperon/spoileron mix using the shoulder slider on my 9c, but when I had my 6xas yet I also flew that using one of the knobs for flaps. don't worry about centerpoint, and like I said you can always use the top half of for spoilerons.

if your SSE is coming in too fast there is something else wrong, that plane should land at a walking pace! you probably have the idle too high, in which case flaps are going to make it nearly impossible to land, it is just going to float along forever.. in fact, landing with flaps down on most beginner/intermediate planes is harder then without, and you also increase your chances of a tip stall with the flaps down.