Long term use of a Urethral tube in chastity

Urethral tubes have always appealed to me. I previously tried a locker 2 knock-off, but ran into some issues. First off, my foreskin reacted poorly to the metal in the capped device, leading to significant swelling. Secondly, when flaccid, my penis is nearly invisible, so the metal ball would either lodge right at the tip or pop out entirely. If it stayed put at the tip, I suffered sharp pain. Consequently, whether I was flaccid with a swollen foreskin or had the ball popping out (causing the device to fall off), neither scenario was ideal; both led to discomfort. Since I am circumcised, the swelling might not be an issue for me now. I’ve also seen similar devices featuring long plastic tubing. It’s not my top pick, but it could serve as a solid compromise. My wife and I are expecting our second and final child, so discussions about permanent chastity have begun to surface. I’d like to hear from others: what has your experience been with metal versus plastic urethral tubes during long-term wear?