I've played two "Organ Traffickers" ghoul chop-shop maps in a new 0.99J2/J3 game so far, and found that in both cases, there was a problem with ghouls spawning on the roof with no way for them to get down from there, and naturally no way for non-flying soldiers to get up either.
Not entirely sure if it's unintentional (i.e. a bug), but sure looks like it.
Example image for last of the two maps attached.
I did crudely highlight two things there:
A. Maybe issue can be easily solved by adding vertical ladders to these crosswalks (or in the corners there)?
They seem to be above otherwise empty areas anyway, and seem to be ubiquitous enough to always provide reliable access.
B. Roof itself is separated into twothree areas by fences, which probably means that adding sparse entry points (like 1-2 per map) might not be sufficient to access all of it.