Since I don’t have smart utility meters, I simply gave up on manually tracking data and added all my metered devices to the main section.
Sadly this is a workaround and you can’t use it together with the measurements for your whole house, or solar power, returned power, etc, but… it’s also sad to see such a basic feature taking dust for 1.5 years already.
I know it’s not easy to implement at first glance, but there IS already a graph that does exactly that, you just have to shift the inputs around - how hard would it be to replicate the graph for individual devices?
BTW, this is definitely a dupe of Energy: Cost for the individual devices
I would suggest closing here and concentrating votes there 