In order to hover a 10 lb airplane you, obviously, need to provide 10 lbs of thrust. Many different RPM/diameter/pitch variations will provide this amount of thrust. However, the amount of drag from the propeller will determine the roll coupling during hover due to the resistance of the prop to movement through the air. The propellers efficiency will be a factor in the drag it produces. Higher pitched props are more efficient at higher air speeds. Lower pitched props are more efficient at low airspeed. More drag is produced with the higher angles of attack associated with high numbers of prop pitch.
During hover, the engine/prop are making static thrust since we really don't have any flying speed. Higher pitched propeller are much nearer stall at low forward speeds.

Given these assumptions I would expect:

Larger diameter prop => More torque coupled to airframe.
Lower pitch prop => Less torque coupled to airframe
Higher prop efficiency => Less torque coupled to airframe


If there are no ailerons within the propwash during the hover, you cannot cancel the roll coupling with those controls.

Hope this helps,
Lloyd