Since it looks like you are going to do a bunch of holsters I'll chime in on how I do holster edges.
Once the holster is sewn, I hit the edges with 80 grit sand paper on a 4x36 inch belt sander that my son in law bought me from Harbor Freight. Once the edges are even, I wet the edges. Then I hit the edges again on the belt sander with 120 grit paper.
Next, I edge. Then I dampen the edges again and slick the edges with glycerin bar saddle soap.
Next step is to use denim or canvas rubbed briskly on the edges. For this, I set up my drill press chucked with a spool that I loosely wrapped with denim. I think I get a better burnish mechanically than by hand. I used to chuck a wooden drawer nob in the drill press and burnish more, but I really don't think it improves over the denim.
I usually dye the edges after forming. I use a 1 inch foam brush to dye the edges if I want a different color than the holster body.
I do not use any wax on the edges anymore. I could never really stop the edges from rubbing off or bleeding when I used wax or whatever.
Hope this helps,
Jeff