Good for swallowing up if something goes wrong (let's say, at a border crossing) or for places where the stuff hiding is a primary concern (let's say for those who are jailed).
Unless this hardware wallet ring becomes immediately conspicuous for anyone looking at it longer than a second, I wouldn't worry about it. People own various pieces of jewelry that they wear and cross international borders with all the time without any problems. If you get jailed, you'll have your valuables, such as jewelry taken from you by the officers, to be returned upon your release.
Actually, there is a worry - you could get robbed, or held at gunpoint and be forced to hand over your jewelry. Sure, the crooks will not the least suspect that your ring is actually a hardware wallet storing thousands of dollars worth of crypto (but then again, why are you carrying it
on your hand everywhere in the first place?), but it will be, at best, a hassle to recover your coins, and, at worst, a crypto theft.