Tom I believe the entire premise is that the beam is much more efficient at dealing with high frequency vibration than the tire. This is where the gains are supposed to come from, allowing you to ride with higher tire pressure without the Crr loss that is associated with high tire pressure in the real world.
If you truly believe what you wrote above, then you have a complete misunderstanding of the sources of rolling resistance in a bicycle tire and how the pneumatic tire construction acts as the most "efficient" suspension you can get.
In short, you WANT the tire to take up the deflection because it can actually RETURN the energy (most of it...minus tire internal losses) back to the road surface in the trailing half of the contact patch. Use a tire with low internal losses, and "Voila!", you have low rolling resistance on ALL surfaces. Remember, it's the "torque arm" caused by the difference in energy absorbed in the leading half of the contact patch and the energy returned in the trailing half of the contact patch that is the source of rolling resistance.
In contrast, any energy that makes it "past" the tires (e.g. if they are too stiff) cannot be returned to the road surface as the tire does. It needs to be dissipated somewhere...either in the rider, or in a damper of some sort (i.e. read "beam"). That energy needs to be supplied by YOU to keep going forward. Sure, you may have actually reduced the rolling resistance of the tire
by stiffening it up,
but the total "resistance to forward" motion is overall higher.
Take a read again through my ST articles on "Tires and wheels...", "What's in a Tire", and "What's in a tube". They're in the Tech section.