There is a limit in how many coverages you can have in a model. I found out that number is 10001.
Whenever I add a new coverage either by shp import or draw by hand, one of the existing coverage will dissapear.
Several of my workflows generates quite some coverages including one that involves "txtexp" > "mapexport" text objects in C3D> import .shp into IW360.
These workflows become completely unusable once you hit that limit.
In the attached screenshot you can see a big rectangular area with exactly 10000 small rectangcles, imported from a .shp file.
I imported 4 more coverages on the left, resulting 3 of the coverages will dissapear in the center bottom.
Please increase or even remove this limit!
Thank you for reading!