
The idea is similar to what you did with the round room, where windows snap into designated areas and connect when you place another window in an adjacent selectable area. I think this approach would avoid having to create an entirely new system for movable vehicles just to achieve the same window customization options available in a normal base.
This would allow players to customize the vehicle however they want while still being able to place walls and create different rooms with windows.
Subnautica is a beautiful game, and windows are one of the best parts of it. Since this submarine is a lot bigger, I think players will take advantage of using it as a mobile base most of the time.
Also, 10/10 to the person who designed the Cyclops and the Trident!
Pictures I took in game showing the different snapping points, along with a random image.