You should have seen the first tech demonstrator for the Raptor engine (the family that powers Starship). It was basically a water tower (built out in the desert, welded by people specialising in building water towers). But it flew, and it landed, and then it served as a lights & camera mount for the field for a few years.
I wonder how many potential designs they considered. You've got the mass of the doors and structure of the ship to consider, the mass of the cargo, actuators for both, the arrangement of cargo in the ship, all of which have interconnected tradeoffs.
Also add pressure management, warping of the dispenser and ship hull & thermal expansion.
And fornlong duration missions also lubricant evaporation, possibility of vacuum welding & atomic oxygen reactions if you spend long in low Earth orbit. :)
The fun thing is that as long as you have the requirements and acceptance right, this could still be solved with a garage door opener and welded rebar :-D