On any of these semi scale "IMAC" types -- wing loading is everything -
you simply can't build these things light enough - Impossible
No amount of clever airfoiling will fix these being overweight. None Zippo -Nada
The problem simply put is that these planes must utilize a very broad range of speed and controlled attitude
Formula ?
lots of power - extremely low weight.
Don't believe me ?
look at the winningist full scale areobats - that IS the formula.
So -just lookat all the construction methods YOU can use - pick the lightest and build the wing with a simple 12% (aprox) sym section - stiff and strong count a lot.
forget any washout etc..
you want a wing loading -on this size -for aerobatics and 3D--under 30 oz ft --also power -2-1