Thanks for the reply and kind words! I'm happy to answer questions.
The Boot Sequence Clock starts when the Reactor is powered on (second bullet point under The Reactor). There's also an implication the AI/Sensors have access to the Airlock Doors unless overridden. Hence, 00:00 on the Boot Sequence Clock begins with some of the Sensors getting pulled in and repaired, while others begin surveying The Cargo Hold seeking for test subjects haha.
But there are ways around that for sure! The PCs can open/close the Airlocks in Control. And that's part of the fun! When we did playtesting the events of the Boot Sequence Clock were often thwarted or pushed up depending on what the PCs did. For instance, pulling Faust out of the Reactor Room meant the Sensors could grab him and repair him quicker.
That being said, if the Sensors are ripping entire walls off, I'd say it's only a matter of time before they can tear through an airlock ;)