Oh, yeah, forgot to mention that. The swivel allows you to go all the way around and pull off the burr in a single pass. Satisfying!
Re tool steels, I almost never saw simple steels like O1 until I started woodworking. All the tooling in the machine shop was HSS for non-ferrous, and carbide for harder stuff.
I don't have any HSS chisels, but I do keep a couple beater chisels sharpened at 60-70 degrees for metal or metal-adjacent situations.