Not re-purposing ... but FYI I have had luck with getting warp/buckles out of self healing mats (mine is an Omnigrid). I had stupidly IRONED something on it. Yeah I know ... not one of my brightest moments.
Anyway .... if you want to re-use the mat as a mat, or need to get the warp out to use it as something else, you might be able to fix it. I use the same fix that I use to give my mat a good cleaning (and "healing").
Saturate several towels with HOT water. Spread the towels on top of the mat (the mat should be on a flat surface). Place a piece of plastic over the wet towels, then place a lot of books over the top - make sure the books fit snugly to each other so as much as the mat is covered with weight as possible. You may need several layers of books. Leave the mat like this for at least 2 hours.
Have everything ready before hand - books, plastic sheeting. The sooner you place the weight onto the hot wet towels, the better.