Ok, I see what your doing now, and I tried to map my throttle to different stick settings, it didn't work.
Ive got an X-52, and tried to reverse the setup, put the throttle and slider for RPM on the normal settings, select throttle 2 and rpm 2 and swapped them, then selected Stick Setup 2, they didn't swap.
Any of the other mappable stuff clearly work, but I can't help you on the throttle part. I retract my suggestion that it does, I cannot make it work, so back to "it might" but I don't know how.