RE: What plane is this
If the airfoil is generating lift, then there is a pitching moment, and there must be a stabilizing force to counteract the pitching moment. It might not be visually obvious, it's just that at high speeds the required lift coefficient is low, so the angle of attack is very low and thus the elevon deflection very small. But it is there, and it is needed, unless the airfoil has reflex in order to generate that force without deviation from the airfoil profile via control surface deflection, or a twist is incorporated into the wing - same deal different wrapping paper. If it is trimmed for level flight at speed with no stick pressure, no way is it trimmed for inverted level flight at the same time.
MJD