From what I can ascertain from the photos it appears that the wing camber fold is approximately in the centre of the wing at the fuselage and at around 30% of cord at the wing tip. This unusual wing planform has resulted in a wing that will generate the majority of its lift at the wing extremities and very little over the central portion, (50%).
The reason for the tail down attitude is the need to increase the wing incidence on the outer, (Lifting), portion of the wings so that sufficient lift is able to be generated to allow the plane to fly. This also allows the central half of the wing to contribute to the total lift but only a very small amount.
A revision of CG position is unlikely to correct this condition!
Bringing the wing camber folds forward and perhaps curving the wing tip TE upwards slightly will balance out the lift a little better and thereby provide greater lift and a more level tail flight attitude.
A simple test of my estimate would be to remove the wing tip extended TE and see it the plane will fly at all. If not then my argument is valid and a newer wing profile design is indicated.
Nice idea otherwise!