What I am implying is that your implication is very misleading.

Your statement, "Dihedral make no difference as to whether or not you can fly a model inverted." implies that a plane will fly as easily inverted as it will upright.

CAN a person fly a high-dihedral winged plane inverted? Yes.

Can a beginner (who is most likely to be flying this type of plane) do it? Doubtful.

You can also stand on a beachball in a swimming pool, but it's not as easy as it sounds.