After you download the ICC Profiles and associated am1x files from Hahnemuhle, do you use the Media Configuration Tool to load it? That is what I do, and I too have duplicates. BTW, Canson has a pretty good instruction pdf on how to use the Media Configuration Tool for am1x files. I have a copy here; it is the pdf that starts with "MCT...":
https://www.dropbox.com/sh/sx6pkuphb76scvp/AABILHA3LX7ZPRMh0sb1uVXaa?dl=0
If you click on each duplicated profile while in choosing a profile in Qimage One, you will notice each copy is in a different folder. Many of them are in your user/library/Colorsync/Profiles folder, while the duplicate is in Library/Printers/Canon/BJPrinter... folder. I suspect this duplication occurs when using the Media Configuration Tool. It takes the profile, which you may have already placed in your user/Library/Colorsync/Profiles folder and adds it to the BJPrinter folder. I am guessing that folder is what communicates with the printer itself. Qimage One simply looks for ICC Profiles globally on your computer and reports back anything it finds. I do not know of a way to limit its search, so the only way to eliminate duplicates is to remove them from the duplicate locations. I might do this when I get around to cleaning it all up, but I do like having the profiles in that user/Library/Colorsync/Profiles folder for backup reasons (I may want to do a clean OS install some day and want those profiles). Since the profiles really are duplicates, it doesn't matter which one you choose. I am more interested in purging all the profiles for papers I will never use than worrying about the duplicates.
It would be nice if there was the ability to restrict Qimage One's profile search to specific folder(s), but I do not know of a way to do that.
Dave