This is especially good for blood hunters who lose a lot of health quickly at low levels

With a short rest. Using the Dwarven Fortitude feat, whenever you take the dodge action. Casting the spell Wither and Bloom, if you're the one who gets to regain HP. I might house rule it to apply to the fighter ability Second Wind, too, since that's only usable once per short rest.

if you've lost your head, you're already dead. that's a moot point

My DM gave me one of these after knowing that I took the remarkable recovery feat from the Tal'Dorei campaign setting reborn...I don't think he thought this through very well.

DM of my game made me take exhaustion when I needed this ring. So yes I could stabilize, but at a cost once recovered or healed. 

Sure does combo well with Gambler blade swords!

Necro-reply to this 2-year old comment, but Prone gives ranged attacks disadvantage and Unconscious gives all attacks advantage. You don't pick which one is more specific than the other, they both apply and thus a ranged attack against a prone, unconscious opponent will have atleast 1 instance of each, canceling eachother out and making the attack a straight roll.

May make durable in 2024 not completely useless for ba heals

nice

That depends, if you don't spend hit die on a short rest, do you still heal your CON value? If so, first one, if not, second one. I use the game app and don't actually pay much attention.

A death dragon's cataclysmic breath weapon (Shadow of the Dragon Queen campaign) reduces a character to 0 hp. The  character wears the periapt of wound closure. Will the character be saved by instant death? According to my interpretation, the periapt states that you stabilize whenever you are dying at the start of your turn. The breath weapon says that you are dead as soon as you reach 0 hp. You cannot be considered "dying", because you are already dead at the start of your turn. 
Am I missing something?