The Rod is immovable in relation to what?

[Greywander]

Nothing says you can't ignore that, of course.

Hey, it worked for the Titanic, right? Nothing like having poorly thought out safety mechanisms that only provide a false sense of security and don't actually prevent a disaster.

I'm only half joking, by the way. Implementing a safety mechanism that doesn't work could make for an interesting bit of tense drama. Definitely allow a player to notice something is off about it if they have the right proficiencies/a high enough passive Perception/Investigation.

Edit: For example, perhaps this was a safety regulation that was implemented when airships were smaller and lighter, and it never got updated. It's the law, so manufacturers still have to implement it, but it's never/rarely been an issue, so they've never updated it for the newer airship specs, and when anyone asks about it, they convince them that it will work and there's nothing to worry about.