I think a great feature would be to have a customizable/configurable Header Toggle in Lovelace cards. Have the option of using the default actions (turning everything in the card on/off) or using a customizable action (turning on/off a switch that’s not an entity in the card). I have a coffee pot Lovelace card where having the coffee pot switch would way better where the header toggle is instead of having it as an entity in the card itself.
Are you familiar with headers & footers?
I agree, it would be a nice feature to have.
I have 1 card for my shutters (covers) and having the header toggle to open/close all of them at once would be the most elegant way to proceed.
Adding a button in header or footer is taking a bit more space.