Chastity and orgasm denial discussion

My boyfriend and I recently tried the CB6000S, but we sent it back because the ring didn’t fit well. We’re getting a cage now and are slightly worried since its diameter is nearly a centimeter smaller. The old model’s cage wasn’t uncomfortable, though skin did poke through the openings until he was fully flaccid due to that style. This new one features a metal stainless steel design rather than plastic. Is a smaller diameter better or worse? I’d appreciate your thoughts!