The CG is a valid issue, and of course the cabane could be adjusted as to some degree the engine mount as well.
The Pietenpol had an cabane that could be tilted forward and aft to adjust the CG acc to the weight of the whole bird.
So if we take just the philosophy of the Pietenpol idea, and transfer it to the Double eagle, some very few modifications would be required, almost invisible from the outside.
If the wing attaching would be made on a aluminium square tube, and this tube would be attached to the fuselage by two steel u brackets, the whole wing could be moved by several inches forward or aft, without altering the look of the bird.