Q. I configured a new prefix to be assigned to all document IDs, but I still don’t see this to be working for an existing document. Did I miss something here?
A. The existing document IDs will be reset only if you selected the Reset All Document IDs in This Site Collection to Begin with These Characters option while configuring the new prefix. Also, the existing document IDs would change only once the Document ID Assignment job executes. You can try to run this job manually from Central Administration as well, or wait for it to run as per the schedule.
Q. Can I have more than one content type publishing hub?
A. You can have more than one content type publishing hub as well. All you have to do is create the same number of Managed Metadata ...