Quote - And what is the path to this mysterious place where metadata is backed up to? Is it to the same location as the database files?

The metadata files are in the runtime/support folder of your DAZ format libraries. DAZ Studo seems to save the user data in the first DAZ format library on the search path. The file is called "UserData_1.dsx"  Most of the files in these directories will be named "DAZ_3D_xxxx..." so just go to the end of the list to look for the user data file.