In any case, since glycerin is readily available in every chem lab in the world (ok, ok, there's likely one somewhere that doesn't have it), and since PP is so common that it can still be found in old-fashioned first-aid kits, why mess with mag fuses, eh? Just layer the PP on top of/next to the thermite mix, tape a firecracker with a long fuse to an eyedropper full of glycerin and lay on top of/to the side of the PP, light the fuse and foutez le camp.
Much easier. Works just as well, for those who are of a mind to burn things down. Sure hope such idiots don't, ahem, accidentally trip over their own shoelaces while beating feet away from the target site.
That would be, uh, ...uh, ...tragic, wouldn't it?
HS chem labs use 1/4” magnesium ribbon, which doubles as a fuse, because it is reasonably stable. Heat it to about 900F and it will burn at 3100F. But in many states you can buy the equivalent OTC, with fireworks sparklers. Which make superb fuses.
I once got some sparkler great granddaddies, used by miners to ignite mine explosives, in lower tech, smaller mines. About 2’ long and about a third of an inch thick. It was a big help to have welders goggles.
It’s much harder to get your hands on finely powered aluminum power and powdered iron oxide.
It was probably a good thing that back then we couldn’t get our hands on an appreciable amount of titanium. But we learned so much that by the time we did HS chemistry, we were really respectful of incendiaries. And inflammables, compressed gases, gasoline, dust initiators, and any and all types of explosives.