Hi - I have tried chastity off and on for a couple of years. Usually, I get running around and have not found the right cage although I have tried a batch. The metal ones are too heavy and the plastics are too bulky. I am locked by my choice, no one else's. Always felt that my cock was sort of small and the chastity cage sort of lets me accept that and move on. I am a bedwetter too if that makes any difference to anybody and wear diapers at night. I am interested in finding new cages to try.
Welcome to the site. Hopefully you'll find what you need. I don't know which metal cages you've tried that you found too heavy, but that's not been my experience at all unless it was horribly over sized. That being said, I do prefer wearing underwear with more support than boxers while wearing a cage so that's less of an issue. Are you a boxer man?
By the way - my avatar is taken from the Cherry Keeper album (https://imgur.com/a/WXonD28), which is what I am currently wearing.