I slick everything that is smoothout. Holsters, sheaths, scabbards, belts, can't think of anything veg tan and smoothout I don't slick. Got this deal from a local saddle maker years ago. Dampen your leather and when the color comes back and then slick.
I think rounded edges also last longer on a product. I've been thinking on doing a wip on finishing edges so I will here shortly.
I use Osborne edgers for the most part but am very fond of a Ron's Tools edger a #2.
It's simply the best edger I have ever used. Period. But they are spendy at $100 a piece. We keep talking about getting the whole set but haven't yet. Very easy to resharpen they package it with a rod that fits in it perfectly to use for sharpening with 600 grit. Then half a second on the buffer and its a laser.
I use a #4 Osborne for most sheath work on an edge that is multi layers. On an edge that is single layer like the throat of a sheath I use a #2.