Interesting. I did a LOT of shopping around and spreadsheeting of specifications and costs when I was looking for CFB recently and never saw this Calcium Silicate product. 1700 degrees F is not a high
enough rating though. And $189 for one board is way too much for something sub-par when you can get 2300 or even 2600 F degree rated material cheaper. I am intrigued by the "no dust" claim and I'd love to get my hands on a sample to see how strong it is. It might even be great for some parts of a
rocket stove, but that temp rating is too low for a heat riser and sketchy for a firebox.
I might trust this to surround and insulate refractory material, like a way to contain and support fire bricks in a batch box core. But as your fire contact material, I'd be weary.