I can’t answer the second question, but as to the first my understanding from the video is that the ignition cylinder starts out as much lower pressure that the

I can’t answer the second question, but as to the first my understanding from the video is that the ignition cylinder starts out as much lower pressure that the fuel/air chamber, and as the slide valves open the mixture naturally moves from high to low pressure. The heat contained within the cylinder starts the ignition of the mixture upon entry (hence the name of the engine). I don’t understand how the heat differential between the injection and ignition phases is so great that ignition happens as the slide valve opens, but so little that ignition doesn’t happen within the fuel injection chamber. Perhaps the pressure differential regulates that as well?