I have had large lumps of metal at red heat on a 3/4″ skamolex block, and its possible o pick up the block by parts which weren’t drectly heated afterwards.
I have some much thcker (1 1/2″ x 15″ x15″) blocks which I will make a hearth with one day. I imagine they would work as space-shuttle tiles

I plan to make a simple box for the tiles out of a biscuit tin or similar as I don’t imagine any dangerous heat getting though, though I do any big jobs outside, only ‘cooks blowtorch’ or turbo flame ones indoors.
The problem with skamolex is that flux sticks to it, and then causes pitting when you break any items stuck to the block off. I am still searching for something suitable for a suitable ‘pad’ to place on the skamolex to protect it.
Neil