Old powder if anything becomes less powerful over time, so there's very little chance of a kaboom with old powder. If anything, you just wouldn't get top velocities you'd normally expect.That's info I just learned, regarding IMR 3031.
Again, for me, it may just be an abundance of caution - but when it's involving a controlled explosion close to my face, I'm going to err on the side of caution.
With that said, Alliant has a batch of Unique that was produced in the late 1800s that they test now and again - it still burns at original spec.
I get it though, and with reloading, it's always best to be safe rather than sorry.