Re:No, you can’t save £30 per year by switching off your “st...
by NordSteve on Wednesday April 27, 2022 @09:52AM
(#31179889)
Leviton offers what you describe:
https://www.leviton.com/en/products/residential/load-centers
Though obviously it’s still only on per-circuit basis, and if an idiot wired your house that may be less useful than the platonic ideal of house wiring.