On a home solar system, start the washing machine, dishwasher, and dryer that were loaded in the morning when the batteries reach 80% charge. Allow them to run off the inverter rather than taking the charge/discharge losses involved in battery storage, reducing the size of both battery bank and solar array needed.

If thats such a world ending colossal issue for you (hint. its not. literally no one will ever have that problem, but lets humor your ridiculous made up bullshit), then https://www.amazon.com/TiFFCOFiO-Mechanical-Electrical-Outlets-Repeating/dp/B0BCKDTS1G. Cheaper, more reliable, and doesnt open your asshole to the internet for fucking.

Lower the freezer temperature when there is a power surplus, and raise it back to normal when not so that cooling energy is used when it’s cheapest/most available

Literally a waste of money and power to buy a thing thats even capable of playing that stupid game with temperature digitally. Set your freezer to -18c/0f and leave it the fuck alone. If you want to save power and be more efficient, get a chest freezer, and make a diagram of whats where inside it so you can grab it easily without fucking around. Anything else is just a completely made up solution in desperate search for a made up problem to justify it, by and for people who have far to much money and far to little common sense.

Your ridiculous stretching to try to justify smart bullshit is doing nothing but showing how useless and how much of a waste of time, energy, and effort it is.