Has anyone tried putting tile directly on Micore with no Durock / cement board? I want to keep the hearth profile in front of the fireplace as low as possible. The Micore 300 specs out with enough insulation by itself, with tile on top, but I have my doubts as to the strength of the bond between tile and Micore if I do not use any cement board. Ideally I'd like to thinset the Micore to the plywood subfloor, then thinset the tile directly to the Micore. Your thoughts?