[Closed] Slate Slab Behind Wood Burner - Will it Crack?

I am considering putting a piece of slate 600mm x 900mm x 30mm thick on the wall behind my 4KW Cove 1 burner. I was proposing to attach the slate to the wall with a single 10mm Thunder bolt. The hole in the slate will be 12mm dia, to allow expansion and movement. The thinking behind just one fixing is not to restrain the slate but to allow it to expand.

Distance from stove to slate will be approx 100mm.

Will the slate crack?
Would I be better off with 3 x 600mm x 300mm pieces to allow for thermal expansion?

In my experience the wall behind the stove gets quite warm. Much more than under the stove.

John