This would be a great feature. I'm on a grandfathered plan so I have to watch my data. I always forget to turn data savings on and off when I switch between wifi and mobile data.

I still have a metered data plan, and I always forget to turn it on when I'm off wifi. Is there a way for the data saving to turn on when I'm on mobile data but turn it off when I'm on wifi? Could that be a feature?