I drew it,... they built it.
Ah! I would love
to see an illustration or photograph of the dry dock's intended upper surface on ProbertDesigns.com if and when you find the time. May I ask if you recall whether Magicam also built miniatures of the additional "clip-on" habitat modules featured in this sketch?
The people at 'Magicam' decided how it would be best supportable, considering how fragile the components were in the real (film) world of a one-g environment.
Regarding your original triangular-truss dry dock concept (the miniature of which you surmised would have collapsed under its own weight on the mo-con stage), is this the speculative real-world fabrication mechanism you had in mind when designing it?
How ironic that now, when CGI technology can render delicate, filigreed microgravity structures just as easily as it can a lead pipe, we get overbuilt docks
that look far more like something to be found in a Tulsa car wrecking yard than LEO/MEO.