Ive played with the jig and the Herret looks workable. Cutting 9x19 down to 9x18 makarov does not.
My first attempt at cutting down 9mm for swagging did not work but if you want to trim it way back and then use your existing trimmer to true it then it is entirely workable. I just dont know how much time you would save.
I built a few custom ones and a 308 version works too.