[Cory]

I see no real safety risk associated with magnesium in the operation of the robot or in the pits at an event.

That being said, you could burn your shop down if you are milling/turning/sawing it and create fine chips that accumulate and aren't cleared out of the machines.

I don't think it really functionally offers any advantage either. there are very few non-power transmission areas on a FRC robot that benefit from more advanced materials than 6061. Those that do you're usually best off with 7075 or 4130/4140/4340.