I did cut mine - not the middle, but the edges. I also used scissors, 'cause I'm afraid of knives. It DID leave a line, but I bent the cut edge away from where the paper would go (is that confusing?), and then it didn't anymore. I guess if I were to try this, I would use my cropadile (or whatever) to punch a big hole in the center, and finish the job with scissors. I am still scared of knives.
I did this to my circles and flower-circles, and swiss dots folders so I could repeat the pattern on cards that were bigger than size A2.
At the worst, you could buy another embossing folder if it didn't work out. Or... maybe buy another one FIRST, just in case. Keep the receipt and then return it if it does work out all right.