I like the rounded bottom jimping; I use a Dremel carbide bit, but it doesn't leave a nice, clean look. I tried using a DC etcher for jimping and it does work, but takes a while and doesn't always leave crisp edges. I may cnc out a template for each side, harden it and clamp to the side of the blade so I get more even jimping by hand with the dremel. The other way I was thinking about was getting some threaded rod and spacing cut off discs with some washers between the cut off discs and using that in a dremel or something?
I saw some guys drilling holes in the spine (left a bit wide) of the knife pre HT and then grinding off half of the hole on the spine when finishing. I found blades to smile or frown during heat treating, so I leave more meat around the profile so I can grind the profile back, so it would be hard to do this method.
I wish there was a 10 LPI checkering file as well!