Most competition guys who run that mix have it on all the time. They have found that it is needed on most lines whenever the rudder is applied. Firsts find out if you too need it all the time. If so, just make sure all switches are inactive on the switch selection screen, and it will be on all the time.
Very true of both the contest and the non-contest flyers. For a really simple reason. If the rudder causes pitch changes, it screws up one of the most important uses the smarter flyers use the rudder for, steering on takeoffs and landings.
If you look at that mixing as many do, it takes on a more sensible perspective. It's making the rudder function just a yaw control function. And what's bad about that? Nothing.