I totally get what you explained. In fact, I do as you suggested and collapse the stacks in order to help me find my non-stacked notebooks. However, it does take time since most of my stacks are expanded. Thanks!
Is it just me that finds the notebook layout page a bit hard to navigate? It seems that I spend a lot of time searching for a specific folder (without using the search function). When a master notebook is open, the gray sub notebooks blend in with the other notebooks that do not belong with a master notebook. A slight indent is the only differentiator. maybe there is a way to color code the folders to make it a bit easier to navigate. Just curious