I find my costs to perform extras higher than doing the bulk work. The program will backtrack to the root directory and you can switch to different directories or drives for that matter.
Some people like to keep all their project files including correspondence, drawings, estimates etc.
For ourselves, we prefer to use one large hopper type directory and put everything in it. We use explicit file names to categorize the projects and the material in each file. As regards BSC files they occur whenever the program is interrupted. It always seemed so complicated before. The components breakdown is very simple.