Never touched the fire damaged stuff, no telling really, I was repeating what my glass man told me, your probably right Destroyer, (I will keep repeating)
My personal experience was that the wind driven rain saturated the cardboard box the glass was originally shipped in. It was allowed to dry in the 90 degree heat for six weeks, still didn't cut it. I had it explained to me once, something to do with a binder or starch let loose in mine. I had gotten lazy and failed to put a third or so roll of mat back into the plastic bag it came in and we had a storm roll thru. I was nearly done with the project so I completed the project with sample pieces donated by Mini-Craft.
My .02. There are smarter guys than me, I would try it and see what you got. Too many responses contrary to mine. A shame if you couldn't use it. I hope I am wrong.