Kit, yeah that's why I took a couple pieces of the 2000 F. foil to 2100 F., I was testing a couple small S90V test pieces. The foil did keep the 1 inch square S90V from decarborizing but after cooling as soon as I put the pliers to the foil it crumpled and split or broke. It won't do that at 2000 F. and I think it best to do as you have and get the high temp stuff if getting serious about HT'ing S90V or BG-42 blades.
RL