Only design matter . And invisible box in the official furniture library looks... weird. But a separate box to the top menu where the wall,room,poly...etc are and call it cutting edge is sounds as a feature. You actually can put a transparent blue box with that to your plan and can resize it (or bend it or make it sloping ) and its act like the invisible box does now, hide all the walls (and maybe the doors and the windows as well).
Anyway. Thanks again the help. This one of my favourite program to make light but good looking plans Fantastic work.
. And invisible box in the official furniture library looks... weird. But a separate box to the top menu where the wall,room,poly...etc are and call it cutting edge is sounds as a feature. You actually can put a transparent blue box with that to your plan and can resize it (or bend it or make it sloping 
Fantastic work.