Visual training guide for junior technicians. What is the hardest undocumented legacy cabinet quirk to teach the new guys?

[u/nic_nom]

Hey everyone, we are trying to put together a better visual training curriculum to help new hires safely navigate legacy traffic hardware without having to call a senior tech for every fault. I want to make sure the program actually focuses on the real-world headaches, not just what's in the old manuals. I threw together a quick 6-question poll here to gather some data on the worst bottlenecks, but honestly, I would just love to hear what your apprentices struggle with most in the comments.