In some 3d software, they use highlight selections to let you know if you select a layer it has a relationship to another. The way that Bins alert to you to 3d stacks is a visual relationship example. Sometimes when cleaning up projects I'll go and remove layers that are turned off but not know if they are used with an effect (set matte) or track matte in a dense comp. I wish there was a way to know if a layer was being used or not, even if it was a pop up when deleting -- hey this layer is currently being used by set matte on layer 14 and 19.
Thats all.