They also decided to not be able to regulate pressure and temperature in their 'gas chambers' because why would you?

That would be the argument for basically Zyklon I guess. You have to really be exposed to a lot of it to get killed, so it leaking out isn't as big an issue.

The whole Auschwitz gas chamber that the tourists look at is a replica anyways. I would not judge any actual historical gas chambers based on that one.