Given some of your previous arguments, I'm not confident in your understanding of the chemicals themselves. And I wouldn't be surprised if there were additional modifications to what the government ordered, versus what you are aware of.

I especially don't trust it when you say things like the diesel emissions make pressure, as if the Zyklon B wouldn't.

It was also apparently used, though the record says the "blue skin" (it's red) and excrement from carbon monoxide poisoning was too traumatic for the executioners.

I doubt that very much. It's far more likely they were traumatized by the labor of actually killing and burying thousands of people. The blue skin might have stuck out to them, but the incessant murder was probably the thing that actually did them in. This is one of the things that generated the Milgram Experiment, because the National Socialists were looking to improve moral and keep good order & discipline among their executioners. Turns out people's minds start to break when you actively seek to kill people in the dozens, every day, for weeks on end. Even heavily indoctrinated soldiers didn't last much longer. Hence why they built camps, hence why they had Sonderkommandos.