Doesn’t have to be a solid idea or anything just suggestions of how to make it work maybe some ideas on the rooms in each floor for speculation, so have fun with the ideas!
(each will be medium/small size to prevent too much confusion or an airship size mess)
Here is what I think so far the all the area should have an elevator connecting all three floors and the outside, top should be a part but mostly and open area with two interconnected vents and each floor should not have more than three or four vents (the vents only connect to other vents on the same floor and the vent outside should connect to the elevator
Since it is a prison the cells should be on the lowest level and maybe the top level is like a crime investigation/workspace area for investigation and data and the second biggest floor
and the middle area is a living space for people and more like a home working office than an extension of the prison bellow it. The prison itself should be filled with cells and a hall and doors can open and close with vents in some of the cells similar the bathrooms in polus and airship. You can see inside the bars of the cell while it Is closed but cannot walk through it without opening it
the last bit should be the docks the smallest part of the map with no vents a small boat and wooden planks for support and minimal tasks