Well you're right, that is a idea.
I'll accept this but don't implement this until I abuse the hell out of it enough to get out of Bronze
They're actually adjusting Stoneplate in PBE.
In the example: 2,500 hp total, 1,500 "base" hp, 1,000 "bonus" hp.
Current: Applies +100% "Total" hp as "Bonus" hp.
Activating Stoneplate (currently) increases "bonus" hp by 2500, since Locket and Cho ult both scale on "Bonus" hp, this is a huge part of the problem. Total hp: 5,000, 3,500 of which is "Bonus" hp.
Current change: Applies +100% "bonus" hp and +100% "base" hp respectively.
PBE: Activating Stoneplate gives you +1,500 "Base" hp and +1,000 "Bonus" hp. Total: 5,000 hp, 3,000 "base" and 2,000 "bonus" hp.
With this change, it doesn't influence in any way how much hp you receive from Stoneplate, but it does help mitigate the abuse. You have nearly half of the "bonus" hp on the PBE version as you do on the current version, severely nerfing abuseable interactions.