I just joined the wings as they came from the box,but without inserting the plywood joiner part- so maybe a little less dihedral-don`t want to take out aileron servo now to massure dihedral. My plane also has a mix like yours 18% Rudder-aileron linear and 3% up elevator with rudder on my 12 ZAP. Nothing serious,does very nice high alpha slow knive edge passes.

Hope this is of some help.
gerrie