The RAM air suspension is certainly not full air suspension as you might see on a semi. Many differences starting with the semi-elliptic spring to locate the axle.
But I'd agree that the thing being called an "overload" is actually intended to prevent axle wrap, not carry any load. That system will also have some problems with torque jacking of the suspension - they should have stuck with and refined their first attempt. Or better still, licensed the system from Autoflex, who solved this problem (how to easily install true air suspension with no frame mods).