Locket of the Iron Solari solution

Riot has stated they want to rework locket. Both current locket and locket on PBE has issues esp vs (single target) burst. Why not make the shield be based on the missing % HP of each ally champ (a low HP ally will receive a bigger shield than a healthy ally). Like ult. It solves the problem of burst because the shield will be much smaller on high HP % targets but can still have those clutch save moments.