Make the Ring large but, not so large as to touch the other contacts or extend much beyond the relay’s perimeter. See the Gap on mine? That gap is about the thickness of a piece of paper. The reality of it is, they are fairly small for a large part and you’re not making a digital wrist-watch…
I could suggest a dimension but, prefer you/user do the homework…
image below shows HUE relay on actual PCB.
