Lars, I earlier assumed Fire Barrier 2000+ to be intumescent but after studying the MSDS sheet I'm not so sure. Didn't think about it at the time, but my photo record of burn sessions doesn't show much (if any) swelling typical of intumescent products. And, the MSDS doesn't list vermiculite, just calcium carbonate. There are ways to make calcium carbonate products intumescent, so I dunno. I'll look more closely at that particular aspect when I heat some along with the CS1900.
FWIW the 3M latex fire caulks do list vermiculite.
The primary advantage of an intumescent product is the ability to swell and seal a hole left behind when something else burns away or melts. A good example would be a plastic pipe passing through a concrete wall in a building. The fire melts the pipe but the hole is immediately sealed. In the airplane app we have push-pull cables and wires passing through the firewall, but they are mostly steel or copper and won't entirely burn away in any case. So do we really need an intumescent?