RE: Hiperbipe
Your model is 2 metres?
In proportion perhaps 14 or 15 mm would be the same.
Is your calculation about 15 millimetres from LE of top wing ?
Of course either model may be non scale and could not be compared.
Boddo said in his article for the 34 inch "supported at the leading edge of the top wing it was little nose down" & " I was not perturbed by the forward CG"