Well I understand all that but what I don't get, is how you get the final blend between the cutout and the bottle.
It seems that from the cutout network shown you would end-up with a surface made up of four edges, while in the 3dm you provided both the bottle and the cutout have a single edge (therefore MOI can generate the blend).

Is there some way to merge edges of a networked surface which I don't know about?
I tried merging by using join but I always end up with a seperate curve.