Chastity and orgasm denial discussion

Hi there! I’m about to place an order for my first custom steel chastity cage. I believe I’ve got the majority of my measurements correct, but I could use some advice regarding the ring. With my CB6000s, a 45mm ring feels slightly too tight when erect, while a 48mm one is a bit loose when flaccid. Should I choose a size somewhere in between?

Also, which shape would be best? Round, oval, or ergonomic? Since I plan on wearing it for an extended period, comfort is key.

Thanks ahead of time!:)