Found the text of the Canadian EU agreement...109 pages of which maybe 20 say something useful...the rest are filled with protected names of wines and spirits. There seems to be no loophole for whiskys containing flavoring agents.
I too believe that the judgment should be in the flavor. This does require the provision of separate categories in the laws. The original Bottled in Bond Act did not prevent rectifiers from making compound spirits, it did however prevent them from passing them off as spirits that were more costly to produce. Of course, having laws that are more standardized world-wide is helpful too.