I'm not sure it'll fit the desired purpose very well, either.
Just because it's good at keeping very cold things very cold,
doesn't mean that the materials used for such will be good for
high temperature insulation as well.

The heat from the glory hole flame never makes direct contact with the
metal. You line the inside with an insulating material(frax). You can
use a little as a metal trashcan. In this case, the glass work being
done needs an opening larger than a trashcan can provide.