I was in the impression it would add another deck or two before we reach hangar.
Not necessarily. There are only supposed to be 6 decks from keel to hangar, 3 decks for the machinery spaces plus 3 decks. I checked some old photos from June/July 2019 and noticed that back then, some modules were already built 6 decks tall, i.e. some modules already reached the hangar deck a year ago.
I think the assembly plan is fairly obvious by now - they just have to join all the current modules together, and pop on the hangar walls and flight deck. There will not be any more large modules. Any modules that were not 6 decks tall (most are 5) will just be built up as needed.