Sleeping: Custom Chastity Ghost or Evotion Wearables?

Hi,
All devices I`ve tried thus far have been non-custom, and the main issue I have is sleeping.
I`m uncut, a grower, with a flaccid length of 35mm, flaccid diameter of 30mm, so I`ve found this device to be ideal for daytime and exercise wear...
http://www.dhgate.com/product/new-d...uper/387358478.html#s1-12-1b;searl|2791154753
as it has a cage length of 30mm and cage diameter of 33mm, so that I expand slightly in width rather than length inside the cage when aroused, and it is quite snug and comfortable at all times.
I am wearing a 40mm base ring with it, and after trying the Mature Metal sizing rings, 40mm seems to be the ideal size for me.
However my main issue is that night time erections cause the shaft behind the base ring, both above and below the scrotum to swell and harden forcing the base ring forward on my scrotum. I understand the biology behind this.
I`ve tried keeping the cage ring tied close to my pelvis with shoe laces at night but find that too constricting and uncomfortable.
So I`m wondering whether either of the new custom devices from Custom Chastity or Evotion Wearables remain more snug at night and prevent swelling behind the base ring?