Originally Posted by Malcolm H

Looks to be very “generic” as drawn. What is the reason for the two canalisers? Having flown a number of single canaliser models I have always found them more than sensitive enough on rudder. I flew a twin canaliser design for a couple of seasons and found it so sensitive on rudder that it was very difficult to get and keep it in yaw trim. The bottom canaliser is vulnerable to being stood on either by the pilot or helper when ground handling as well.

The only advantage I can see for the double canaliser is if using IC power, it’s a place to mount a second airbrake. Other than that it’s a liability.