This style of design was difficult for a number of reasons, not the least of which was that people find it very difficult to think about shape when they're only presented with 2D slices. Estimating weapon coverage and maneuvering thruster placement was next to impossible.
So of course I told my play testers they were wrong and kept forging ahead.
No, what I did instead of spend about two months re-writing the hull designer to work in the reverse order which turned out to be much more intuitive. Players now design the exterior of the ship first and place their interiors inside that shell. To be honest, I had taken inspiration for the inside-out style of design from Shores of Hazeron, but given how obtuse just about everything in that game is I really should have known this would be a losing proposition.
The best news: people now tell me they are actually having fun with testing, and have even reported firing up the game on their own just to play around with it. So without further ado, here are some example builds.
The next milestone is a few usability improvements to the designer, including the ability to save and load multiple ships instead of always using the same file. After that, it's time to leave well-enough alone and move on to turning these ship models into usable RTS units.