Interesting find. I recall looking into military flamethrower design before. Seems that most things on it are classified. I'm also not sure how much the combustion would change the design conclusions.
On that note, a lot of military fire protection research also seems to be classified, sometimes for entirely unclear reasons. There are some studies on the range of fire monitor streams under wind that I'd like to see, but as I recall at least one of these reports is classified. Secret super-effective technology maybe?