Good evening, @brent_scholar ...
I'm not sure if this is a direct answer to your question, but in this Guide:
How do I use the Comment Library in SpeedGrader? - Instructure Community (canvaslms.com)
...there is a line in the light blue box at the top of the page that says, "Comments you have added to the Comment Library are accessible from each course in which you are enrolled as an instructor." I could be wrong on this (wouldn't be the first time), but I don't believe that comment libraries transfer from one user to another.
I know this probably isn't the answer you were looking for, but I hope it helps to answer your question.