i fly 3w
be sure not to share any connections on the same pins in your plug for wings. some guys share pos and neg on the servos to make the number of pins work out
i used a store bought harness like your making with just such piggy back wires and the last short plug in the harness i used for retracts.. well needless to say when the radio gets turned on the retracts get voltage feed back from pin for the flap servo.. this resulted in both the one main gear i had plugged in to setup wing and the control board to burn out.. got a replacement for both items and im good to go with seperate leads for every use in each wing. yes old fashioned way but i got burned once not going to get me again. and i would have needed 2 molex plugs per wing to make all the connections seperatly powered..