I like to use solid dividers or 1/2"x1/2" if I need to let the chins see each other. Galvanized metal flashing from a hardware store can make a good divider, it's just hard to find in wide enough rolls sometimes. You could make the bottom part of the divider out of a piece of metal and the top out of the 1"x1/2".
The problem with the 1"x1/2" is that they can get both bottom and top incisors through the space to bite at the other chins. It could eventually work because the chins would get used to each other, but at first it could mean toes and paws and noses could get bitten.
I was looking to use it while supervising them. Thanks for the info. Was hoping that would be small enough for them to get up close to each other but not be able to hurt thru it. I guess i will look for something smaller.