I’ve got the Veritas honing guide and it works great for wide plane irons. Like all non-edge clamping guides, it is difficult to tighten the guide enough to keep a chisel from shifting while sharpening.
I came up with a simple solution. I have a sheet of 220 grit sandpaper that I use for hand sanding irregular shapes. It is simply folded in half with spray adhesive on the inside. That way both sides have grit and the backing won’t slide against itself. I cut a small piec of the double sided sandpaper and put it under the sharpening guide clamping bar. It gave enough friction to hold my chisel securely without shifting while sharpening.