I'm not saying it's impossible that WhistlePig and Jefferson's come from different sources, but I think it's unlikely.
In Canada, however, there are two distillers who have found a way to overcome the problems of sticky rye mashes and gummed-up equipment. Hiram Walker distillery in Windsor, Ontario, has solved the problem by using malted rye. The perfect rye-converting enzymes, of course, are made by the rye grain itself as it starts to germinate. The other, Alberta Distillers, which uses 100% unmalted rye, has developed its own proprietary strain of Aspergillus fungus that specifically converts rye starches into sugars.