I suggest the SS-300 is better suited: it has a cut-out on the underside at the edge, so it doesn't contact the outer platter at all.
You're right, just tried it. It is true that the bottom side of the SS-300 is slightly smaller in diameter than my Denon rubber mat. So this must be the right mat for DP-80
I've seen people using it with CU-180 too, but i thought about weight on that spring denon platter. Maybe this is a wrong mat for DP-80.
Has anyone tried this ?