Enveloping Mist Feat Life Cocoon

I have a question regarding Live Cocoon, it isn't temporary hit points so it doesn't use the same mechanic.

Enveloping mists states.

"When you cast a spell or use a feature to restore Hit Points to a creature, the creature is wrapped in a healing mist. Roll one of the dice from the feature that healed it, and note that number as the creature’s Life Cocoon value."

If the creature is healed multiple times would you create Multiple Life Cocoons, or would it just be the one with the highest value, or would the values stack? 

Since you note that number as the creature's Life Cocoon value; i'd say using a feature or spell again would only reset that value. In other words, the die roll result don't add up to the value, it becomes the value.