I dunno man, I had a 2.25 Saguro on the back of mine, geared. With the sliders full forward I was getting mud rub (sounds like a Urban Dictionary porn thing!) on the chainstay and had to reposition back. There really isn't that much room and I don't see the Knard tire being remotely usable even if it does jam in there.
That said, I do love the idea of throwing the Knard on an average 29er frame. Cake, and eat it too.
It's just his way of jumping on the next band wagon and admitting Fat Bikes are cool.
-Jim.