As of right now, all you have to do to skip the maintenance tunnels altogether is find 372's chamber and BOOM, you've got the code.

I propose making the MT code appear on a different document each save, so maybe it could be on 173's document, or 079's document, etc. This would make avoiding the MT harder, unless you got lucky and found the right document early, or refined a document in 914 until you found the right document with the code.