I wonder if there is a nozzle design that would allow for efficient combination of the relative chew resistance of metal wools with the convenience, speed, and R-value of blown foam insulation…
It’d probably be fiddly and prone to jamming; but in principle it seems as though you might be able to carry a nice tangle of metal fibers into place on a blow foam spray. Alternately, perhaps a suitably lacerationous solid formed by a reaction at the interface of a binary blown compound, in fractally hostile structures integrated into the foam…
