Challenge: make a tool (can be an application, script or CMD) that locates and backs up all API add-ins from Revit add-in files. Ideally, this tool would place the result in a ZIP file with subfolders that are logical and could be 'restored' to a new / clean installation of Revit.
Note: if you are going to 'take the challenge' I recommend that you post a comment so that you can co-ordinate with other coders if necessary.
Some of my notes below:
Need at least 2 x add-in folders and any referenced dlls
On my PC:
Wiki - addin locations: