if they are later (or simultaneously) used in maps that do not have the lower level passage displayed, they end up with an inappropriate white (non-passage) space in a location where there clearly should be passage (ie the pit).
Indeed, though I did come up with a solution for that, in the form of a filler scrap at that location which is used when offsetting maps. It's a messy solution though, and it would be better not to need it.
Similarly, scraps with holes cut-out wreak havoc with the loch models.
Interesting! Thanks for sharing that one, I hadn't noticed until you said.
Perhaps a way forward would be a feature whereby a passage fill area be defined that is completely transparent to show any scraps that happen to pass below it.
Genius! I really want this feature. Don't know if it is possible, but I want it anyway.