I’m confused. Are we talking about this Home Connect?
Where are you imagining that the power draw information is going to come from?
Each appliance could send power information, but that depends on them supporting it.
I also just installed the Home Connect integration as I thought there will be a energy entity. Well bummer.
However in case of the dishwasher I suppose there is a workaround: There are entities for every one of the specific wash program and on the BSH website you can find the energy consumption for each of the programs.
I suppose you could then calculate and create a template that divides the e.g. 1,5kWh / 45 minutes = 2000 Watt at any time during the 45 minutes.