advanced mix on TX DEVO 8S

I just recently purchased a new radio (8s Walkera DEVO). In programming-free curve, it allows me to include or exclude (in the curve that I am creating) a possible trim stick or given to a dualrate or any other mix, or just have the original clean signal of the channel. my question is not how you set up, but what is. when and in what occasion do I take advantage of this opportunity?

I hope someone is able to answer to my question quite complex.

It's quite an advanced feature that I do not think is used very often. I had the occasion to try it while doing pirouettes with my miniCP: I noticed that I had always to correct the cyclic in the same direction to keep it still, so I mixed a bit of aileron in the rudder channel and it improved a bit.

thanks for answering. unfortunately I have not yet figured out what the occasion may serve