Eh, I don't entirely agree on that one. We don't actually know how deeply the hangars go, and if they interconnect, it makes for a simple ingress/egress pattern, for landing cargo, personnel, or really anything.
So it's not "solidly established", fine.
My point / analogy is: Just because I use my garage to put our family's bicycles and my junk in there doesn't establish that this is what the garage had been designed for originally (i.e. just because the Saratoga
stores escape shuttlecraft there 80 years later, doesn't indicate what these doors on Reliant
were originally designed for).
If we take a look at Tim Ketzer's faithful and accurate reproduction
there is one unique thing that can't be ignored:
The embayments on the upper side mirror the shape of the doors below. What is this good for and what's the purpose of these upper embayments anyway? I've made a suggestion, let's hear some others.