Hi,
Sorry for the English, this is a bit easier for me.
Last year I mounted a T-can on my Synergy. I found the results stunning. Had to reduce the throw of my rudder with 30%. The tail clearly has to drop less to maintain knife-edge.
The timing of the rudderinput when rolling got less critical too, where previously I had to add a lot of rudder to keep a level flight with change in direction if not fed in at the right moment, now it seemed to be a lot easier to find the correct timing.
Don't ask me for a aerodynamical explanation, i do not have one, but for me on this model it worked. On the other hand, heard from other, and better pilots that they did not benefit from it.
Give it a try I would say. I make them myself now from foam and balsa.
Regards,
Hans Meij (The Netherlands)