I was talking about an existing E7 supply such as mine, and the 'problem' you mentioned has always existed. It certainly existed in the days when I had an electromechanical time switch (which was often not remotely 'correct'), and I imagine that my current 'dumb' electronic meter has a much more reliable knowledge of 'what the time is' than its mechanical predecessor ever had!
My meter has no communications facility (in the SM sense) so, unless it is getting time information via the supply network (which I very much doubt), it must be autonomously reliant upon it's internal clock - which I presume was 'set' when it was installed?
So we still have E7 without a teleswitch? I was unaware of that.
Below is todays rate, for the Octopus Agile tariff.
The published data about wholesale electric costs, would require some smart device which can start processes when the electric has dropped below a set threshold. And to be frank, the times when electric is most costly is a time when 90% of the time I will have battery left, so of little interest to me.
The idea of a smart meter which can be set to start things when the rate is below what has been dialled in, seems a good idea, I know storage radiators can have a command wire to turn them on the heat, but the rest of the devices seem sadly lacking in any interaction capability.
My dishwasher, tumble drier, and washing machine all have a delay start option. All seem to starts at ½ hour increments, but as delay increases go to 1 hour increments, which is a bit too long, and the tumble drier, and washing machine both rotate drum every so often, so wife sets up and tells me to start it when sun is up.
But the chart does not make sense, they are charging around 6p/kWh for car charging supplies, and without a car I was charged 8.95p/kWh which is below any point on the graph. If everyone was to be charged an economic rate, then all the really cheap tariffs would vanish.
The solar rate for export is a good example of the problem, it should be a far rate, what ever the import rate is, but Octopus 4.1p/kWh if not buying from them, 10.54p/kWh with a 30.68p/kWh if between 4 pm and 7 pm which most solar panels have little output at that time, or 15p/kWh if importing with standard single rate.