Is it reasonable for flight economy to correct banking tendencies with stick and rudder? An aircraft with side-by-side seating but only one person aboard should fly banked.  Banking decreases lift and more elevator is needed than in leveled flight which increases drag. Correcting the banking with ailerons and rudder also increase drag. Which is better for economy?
You might be better off correcting weight imbalance with more fuel in the opposite wing if possible.  Then fly with fuel selector on both as long as you can.  This should give you better economy than trimming aerodynamicly.

Notice this also true for weight too far forward or aft.  Good balance helps in the air.