The first benefit other than what you stated, that I can think of for using 2 channels, is the ability to have aileron diffierntial. This can help give the plane a more axial roll which simply menas the plane rolls in a straight line for a longer time which raising or dropping the nose, besides it just plain looks better. Most Cap232's have a good axial roll anyway, but I am not familiar with yours.

Spoilerons is another thing that can be done.