Well when i did my fireplace,Da Man was my insurance company and durock with tile was good enough for them.I built it according to the book.Thier Book!! By doing so my insurance didnt go up.
Good enough for them, good enough for me
Are you sure you have to have this product on the wall when you are using a tile face.Or do you need to use this product if it is going to be your finished wall?
Check your book again, i think you will find that with tile as a finished face,the mineral board is mute.
Ive never seen a fireplace where durock couldnt be used with a tile finish.