I would call attention to Section 3.7 of the manual – MATCH GUN – which uses match heads as propellant. People around the world have been using match heads as expedient “gunpowder” for decades, possibly for more than a century. Match heads contain Potassium Chlorate, typically in the neighborhood of 40-50%, depending upon which country you buy them in.
The warning from Albert & Oelberg (which you highlighted in red) is contradicted by the U.S. Army and thousands of people who have used match heads and other Potassium Chlorate mixtures.
If we had listened to all of the “nay-sayers”, we never would have started making our own black powder, much less our own primers.