Your first point: there is actually NO space above the support beam. Our HVAC guy grabbed a ladder and showed us. That beam is like 2-3 feet deep and goes all the way up. And they can't cut through because we're on a mountain and it has to support several hundred pounds of snow load.
There is truly nowhere else to put the ducting. We walked all through the area with the HVAC guy and suggested idea after idea and there is physically no other location to run it. Hiding it is the only option, as horrifying as it is, unless we tear out the entire new HVAC system (which we can't do).