[kach22i]

It's a tough question because it is presented in 2D, real life and airflow is 3D.

If the Kamback has generously rounded shoulders then it should out perform the aileron.

However, if the Kamback has no sides or has 90 degree edges returning to the hatch, then my money would be on the aileron.

I like the aileron because it causes less lift and directs the air downward better using air pressure and flow differences. However there are bound to be some frightful vortexes forming if not framed with sizable vertical stabilizers (upright wings) which are not currently shown in either option.