Had a lazy weekend but thought this might be of interest.
Here is a mockup of where the s1 engine room will and will not fit in the primary hull
You can see that the top image the pipe structure could fit through the thin section of the hull but the room doesn't rest on any deck.
The middle image and bottom images show the room on either deck 5 or 6. The pipe structure sticks out of the hull if we go by designer's intent and would force the room more forward in the hull.
I'll see what it looks like with a tapered pipe structure and try for placing it in the engineering hull next.