You can just grind the edge off the handle. On my violin knives, I do a little leather wrap around the handle with leather cord. Very comfortable, but I'd be terrified to try it on a lathe at any speed. I keep them insanely sharp. Your idea seems a lot more reasonable.
Once the edge is gone, you could even make a little wood (or whatever) cross guard for it to really protect your hands in case of a catch.
If you tell your tool maker what the issue is, it's probably pretty trivial for them to just provide them to you that way.