Chastity and orgasm denial discussion

My Dom Master wants me to wear chastity gear, though I have always steered clear of it for longer than a day or two because the discomfort is too much and my lifestyle keeps me busy - think gym workouts, long-distance sailing, running, and so on. I’ve experimented with several different devices. On top of that, I deal with tight testicles; over the years I have used many cock rings and am fairly confident about finding the right size to avoid being overly constricted. However, if my balls get too tight after a gym session or run, they pull back up high and can slip out from whatever device I’m wearing. I’ve come to realize that I likely need a custom-made piece for this to work properly, and I see mature metal jailbird as a good source. Apart from the base ring size, I believe the key factor is the distance between the cage and the ring. This spacing prevents excessive pressure on tight balls, but it can’t be too large or they might retreat back through that gap. I’ve also noticed that there is some movement at the pin joint which allows this gap to adjust slightly. I want to ensure the gap doesn’t widen excessively - nor squash down onto the balls either. Another worry of mine is whether wearing the device while leaping around on a yacht, stretching and crouching will cause trouble. I would love your feedback, perhaps some advice regarding fitting and daily wear, or just reassurance that living a ‘normal active life’ is possible without sustaining damage. I am really eager to please Him by becoming His locked slave as He wishes to see how much the device transforms me into a more submissive state so I can please Him even better.