Yes, round chain does look a little "funny" even at that scale - IF you know what it's supposed to look like. If you don't, and think it adds to the model, then I say use it. I've used the flat photoetched anchor chains that come on PE frets for my 1/700 scale ships, and for the small lengths involved, it looks just fine. I well remember the one PE fret that had
individual 1/700 anchor chain links you were supposed to join to get the 3-D effect and I thought, "Nope, not gonna go there..."