When I was making the decision between the 3000cn and the 3100cn, I was not aware of the differences.  From the side-by-side comparisons on the web site, it appeared that the only difference was that the 3100cn came with an additional paper tray.   Now I've learned that it was not the only difference. 

 

So, when my warranty expires in June, I would like to see what I can do about converting my 3000 to a 3100 to have the ability to use the 4K yield toner carts as well as the ability to print from a Mac.   Surely there's some board you can swap out inside that makes it a 3100, right?   All it takes is knowing the right board, and finding a dead 3100 on eBay to gut for the component.