I've seen a lot of suggestions relating to different aspects of dynamic lighting, and all of them are great, but require quite a bit of development time. I might have a temporary solution that could work fairly well, and solve a lot of problems that people are having with dynamic lighting. The feature would be called something like "Memory", and would function very similarly to the fog of war (as far as how placing the fog of war works). Areas that aren't marked as memory function exactly as roll20 works now; if you don't have vision of an area for any reason, the area is simply black. However, areas that would have otherwise been black will instead show a dimmed version of whatever is on the map layer. This would allow for the dm to change around any tokens on the token layer in areas that they players aren't currently in without needing to mess with the dm layer at all, or worry about the players knowing that the area is being changed. It also solves the issue of players feeling stranded in a black abyss of nothingness, which is really the primary issue with dynamic lighting as it is now.