Air gap needed?

I am beginning hearth construction and wanted to confirm the safety of my planned install. The stove is a Jotul F600. The plan for combustible protection is:

Floor: 2 layers Micore 300, 1 layer durock, 1 layer thinbrick.
Required floor protection R value = 0.893
Each sheet of micore is r 1.03

Walls: 1 layer micore, 1 layer durock, 1 layer thinbrick. Total hearth size is just over 7'x7' with clearance to walls well beyond specified minimum clearance to combustibles.

Sound safe to the gurus here?

Thanks for your time folks!

Overkill is ok with me. I want the hearth before thinbrick up about 3.75" from floor level to create a clear step up from the floor and allow me to use cornerbricks as a border. The extra layer of micore was more about height than R value. It was either that or another sheet of plywood and I figured might as well get the added R value.

One concern I did have is with a full inch of micore, do you think there may be an issue with the material compressing under the weight of the stove over time?

Not a bad idea - I will go with a second durock layer instead of micore. Thanks for the advice.

Almost never a waste of money when it makes your wife feel a little safer