Ed, I hope it didn't sound like I was trying to contradict you. I am genuinely interested in hearing of any accounts of these combusting and/or details of how they break down. As you say, I think their typical method of storage staves off the former, but even so, the latter would still be a concern.
Burke/Brace kept theirs in envelopes in file cabinets, which I would guess is the most common storage method for photographers and newspaper archives alike over the years. Most that I have seen of Burke's seem to have held up well as far as the stability of the film itself (though judging by fingerprints, scratches and other flaws, perhaps not handled with as much care as we would have liked). I suppose the basement of a Chicago residence is pretty close to "cold storage" for much of the year
I wonder how they would compare though to a photographer based out of, say, Florida?
Lots of great info in the page you linked to, and the pages and documents that page links to, that I'm just starting to digest. I REALLY like the page with the graphics for identifying film types by notch codes and wording on the film, and only wish that they had included years of production for each film type in the chart as well, though I suppose the actual dates were outside the scope of what they were looking at. I may just have to add that to my ever-growing list of research projects to fill in those dates though unless I discover the info already detailed elsewhere. (That should be read as a subtle plea for anyone to point me to where that info may be detailed and save me from my own ambitions. Somehow keeping nitrate film on the back burner sounds dangerous, even if I am just talking about the dating of it).