Magic Item that boosts temp hp validty

[elyktsorb]

I wanted to know peoples thoughts on a magic item that would increase the amount of temp hp as follows.

"Whenever the equipped character gains temporary hit points, the amount they gain is increased by Proficiency + their highest natural Modifier (IE, if you had say, Str at +1 and Wis at +4 you would use the +4 from Wis, but if you have a Headband of Intellect increasing your int from 9 to 19, you wouldn't be able to use the +4 you have in Int, as for the purpose of this item, it would still be a -1 modifier), the increased temp hp still follows the rules of source that gave it."

Since I know adding an item like this would be hecking broken if the numbers got too high.

[Mastikator]

It would be good when you have a ready source of temporary hit points per short rest or some semi-rare occurrence. And really good on something that refreshes per round, like heroism. It would also be nearly useless if nobody can give the owner temporary hitpoints.
IMO add 3 charges of 1d10 temporary hitpoints per long rest (as an action to activate), those charges may not see use, or they may be depleted every day.

I'd then rate it as a rare item. It should definitely require attunement, and probably make it an item that blocks other magic items, like an armor or belt or shield or weapon. I'd probably make it a shield.

[elyktsorb]

It would be good when you have a ready source of temporary hit points per short rest or some semi-rare occurrence. And really good on something that refreshes per round, like heroism. It would also be nearly useless if nobody can give the owner temporary hitpoints.
IMO add 3 charges of 1d10 temporary hitpoints per long rest (as an action to activate), those charges may not see use, or they may be depleted every day.

I'd then rate it as a rare item. It should definitely require attunement, and probably make it an item that blocks other magic items, like an armor or belt or shield or weapon. I'd probably make it a shield.

I mean the idea is that it would probably go to someone who does stuff with temp hp already.

[loki_ragnarock]

Proficiency plus highest natural modifier is finicky AF.

Just make it Con bonus and be done with it; it's everybody's secondary or tertiary stat. Trying to determine if it caps at 20 or 22 after a manual of gainful exercise is the sort of argument nobody wants to have.

If you have to explain it that thoroughly in the parenthesis - while not addressing all instances - it's too complicated to mess about with.