Update on the runout video (I updated the video to reflect BTW).

I grabbed various rods (mostly tooling bits) and chucked them up. I got very consistent readings across all of them, and saw up to 12 thou of runout!
Same readings on all of the different bits, and all at the same point of rotation (so I doubt they're all bent at the same spot).

What I shot yesterday was really only checking the backing plate, bearings etc. My bad.
I should have checked the chuck as well.

I'll just have to keep this in mind when doing 'stuff' that it better not be that tight of tolerance!
I was mostly going to use it for artistic things anyhow, except for the odd gear.