Hi dear sir pleas tell me,, magician with flaps flies nice... Stabilizer must be longer way?? Thank you very much Jan Novák.
Deflecting the flaps causes a "nose down" torque when applying "up elevator". Normally, you would want a larger stabilizer to overcome that. However, having the ratio of flap movement to elevator movement less than 1:1 can help the issue (like 2 parts flap to 3 parts elevator).
You can do it without any changes, it will just tend to "swoop" into corners.
Brett