I have the flaperons set up as the slave to my elevator on one plane just for the fun of it. As I pull up the ailerons drop as I use more elevator. I have even had the spoileron set up as slave to my throttle, again, just for plane fun! As 2slow mentioned, flaperons can induce a stall and sometimes if I don't flip the switch and turn them off before landing on those nice calm days the plane can be a hand full. Probably not a good idea on a trainer type of plane. You can slow the plane down better by changing the prop. The trainers I have used over the years I always go to a bit longer prop with a smaller pitch to help my students stay ahead of the plane and slow it down a bit for both flying and landing. Seems to help.