Hi AViegarien I don't know if you would be interested in creating a separate mod or if you even have time to do so.

There seems to be a few people wanting wall sections only,
this idea is a similar take on Faydruhs Fay - Lightweight Interior Block Slabs id=1237811942

If you could create a wall section no floor or ceiling which could be placed in 5 different locations on a block left, middle and right alignment as well as extending past the edge of the block both sides possibly just the window wall and a plain wall then you could make variable widths of passageways as well as stacking walls and also allow wall sections to be placed next to other items on a block like seats/ladders almost looking like compound blocks.

Thank you for creating the passageway mod it is a must have in my opinion.