That is an interesting topic for a study. I have read a lot about the Rush and have not seen any focus on your subject.
My interest in the tax records was to try and verify the production of gold from a claim held by a man who married into a distant member of my family. According to newspaper accounts of the day he was said to have made a significant amount on his claim. But, he died shortly after returning from the Klondike and his probate did not indicate any great wealth. Of course the news of the day was full of so much hyperbole it is difficult to believe most of it. But, according to the tax records, which are not available for all years, he did find a reasonable amount of gold.