Taking Inspiration from another project
I discovered how T-Zero Systems built a Subnautica Cyclops (part 2). Great insights, will definitely take inspiration of the red frame "slices" in the middle section to hold the internals.
I'm very much tempted to print a good-looking hull too, now that I know it can work. It would probably interfere with the magnet-based propellers (T-System's design has external, immersed propellers).
This one from CPSDrone was a good watch too Their CPA is so cool, I'm definitely stealing the 3 rods design to slip each module as an array:
Looking at those videos I'm pushed to move motors outside the shell, but since the current design isn't making much damage to the hull, I guess I can continue with it, and upgrade later.
Also, I got myself a printer. A 3D printer. Legos seemed great for prototyping, and to some extend they are, but also I feel like I'm spending spend more time figuring out a way to fit them in the hull, than building a dedicated frame.