I don’t think I explained it well. In general damage works the exact same as it does now when your unconscious, aka not at all.I think you need a scaling number rather than a fixed one, which is why they use Death Saves. Fixed numbers when monster damage scales mean you just get insta-killed a ton after a certain point. Especially as hits on an incapacitated target auto-crit. I know it's off-the-cuff, just pointing out why they don't use fixed values.
You take a hit, you get a death failure. Take a crit, two failures. It’s just now for the purpose of healing, you need to heal an extra 10 or 20 health before they regain consciousness.