Oh I know it's not recommended and why I always comment what I've done so I can do a global search on the files to see what I've modified when an update is available. (I back everything up prior to any kind of core updates.) I prefer not doing it but sometimes I have to. I've been doing it with the Gallery 3 and WordPress code and their plug-ins for some time.
Anyway, I did at least make a duplicate of the Garland theme that I am working on. I had do to a global search and replace for "garland" to "mygarland"; otherwise, it was still using some files from the original theme's folder.
But, I'll go ahead and make that suggestion as it's straight forward and what most user's would expect to happen when IPTC descriptions are imported. Of course, then you have to worry about them having already added the <br /> tags into the IPTC description.. :/
