As I am a relatively infrequent modeller, not yet being retired, and building a fairly complicated industrial layout I found dust was a problem. But throwing sheets over structures like that seen above is a recipe for disaster.
I was also unhappy with my halogen spot lighting and wanted to have something more akin to diffused daylight.
This construction solved both problems. First it is a 'valance' made from thin plywood and timber that holds/hides the lights. Also it is an inverted box supported by rope from the ceiling, and which can be quickly lowered onto the layout to provide dust protection while the layout is not in use.