I use a Veritas inset vise on my Bench-on-Bench. I have to hold some odd shaped pieces for something I am working on. The provided dog has a flat and rounded side. The flat won't conform and the rounded can leave dents if you need much grip (DAMHIKT). Oddly this has never been an issue before since the 3/4" dog in the row of dog holes normally handles this. I am using odd shapes in combination with a Moxon Vise-like requirement; I want to hold the odd piece but, with the edge parallel to the side surface of the Bench-on-Bench.
I take a piece or 1/4" round rod and cut off a piece about 5/8" long. I round the end to match the original dog pins and press-fit it into a scrap of pecan.
Veritas offers a nice rotating dog accessory for the inset vice but, that was there and I was here and needed it now ;-) Took about 15 minutes and I now have a rotating dog which is working fine for what I am doing.