For anyone interested, and prepared to fully read and absorb information, there is more on this subject at:
https://discourse.shapr3d.com/t/how-to-move-a-sketch-into-a-different-folder/5732
For those prepared to administer the situation it is potentially practical for a single Design to contain Hundreds of Sketches.
All perfectly usable and manageable by Hiding Sketches that are not in use.
On a large scale the Administration is likely to be more time consuming than the Design.
Without adequate Administration it would be easy to create a messy situation.
This gives rise to consideration of alternatives. One that I consider preferable, keeps Design File Sizes smaller rather than larger.
One such alternative uses the Files App to contain Folders to hold Design Files and this will ease the burden of Administration.
Importing only Bodies from the Design Files into an Assembly File will keep all things S3D at the usual rapid response rate.