This is inefficiently attempting to solve the problem in the same way while trying to maintain that flat electric rate. We need to get past the idea that electric rates must be flat.
I'm not aware of anyone that does minute to minute electricity pricing, but I know for many utilities you can sign up for alternate price schedules that have different rates based on the time of day.
I would guess as much as anything it's a metering issue.
That's better than 24/7 flat, but is not a solution for dealing with spikes in demand or fluctuations in supply. Minute-by-minute spot pricing is the solution for that. With the ubiquity of the internet, and low cost for IoT, it's feasible, practical, efficient, and effective.
Based on the website it looks like Griddy is something you can just sign up for and then your bill will be routed through them somehow? How does that work? Who maintains the infrastructure?
By your description it sounds you guys in Iowa have a regulated market. There you have a vertically integrated electric utility company who does everything from generation to line maintenance and billing with oversight from a public regulator.
In a deregulated electric market you have separate generator companies who sell wholesale electricity to retail energy suppliers who sell it on to end customers. Transmission companies maintain the grid infrastructure and they are paid by the other participants for this service. This scheme when it works right can result in more competition and thus better efficiencies.
This page seems to explain it quite nicely: https://infocastinc.com/market-insights/solar/regulated-dere...
I know many utilities in my area have a program you can sign up for where they will cycle through the registered AC units to balance out peak load in the summer. I'm not entirely sure how they manage that, I suppose they have to have some sort of sensor switch they install in your circuit.