This latest update loses a lot of the readability of the earlier versions because everything is so dark and there's very little contrast between different surfaces. I like the rimlights and dark mood of it, but you lost both some value contrast and a lot of the hue contrast by darkening everything. I think bringing some value contrast back would help a lot.
I noticed even in the very first post, the wood panels on the centre "stage" are more textured than any other surface in the scene, to the point of looking out of place.
This is probably too big of a thing, but have you considered having the window curve, either horizontally or vertically? Being so flat, it makes this place look like an underwater section of a building (typically blocky) rather than a vehicle (typically rounded).
The huge size of the window also doesn't help with the "submarine" look, I think having some reinforcing beams running across it would help it look more like something built to withstand the water pressure.