Questions on Ring Size and Slipping with Jailbird Cage

I am wearing the jailbird steel cage. It came with three rings: 40 mm, 45 mm, and 50 mm. I have been using the 50 mm one since day one, but lately my scrotum has softened as I get accustomed to the device, causing it to slip down slightly. This lets my balls drift between my legs where they can get squashed.

As a temporary fix, I’ve looped a shoelace around my waist and attached it to the cage to keep things lifted a bit more comfortably. To stop the slipping issue entirely, I attempted to switch to the 45 mm ring, but fitting it on seemed nearly impossible unless I really forced it.

My questions are: A] Will switching to the smaller ring fix this? B] If I manage to get the 45 mm ring in, will night-time erections hurt more? I don’t want to wake my wife up just to ask for the keys! I would appreciate advice from other jailbird owners.