We ran AFFF systems in race cars. They are maintenance intensive.
And the AFFF gets in the groundwater, requiring not-cheap filtration and testing to ensure removal. Ask any military installation, or a city with a fire training facility. I’m dealing with a city affected by a military installation, right now.
Yes, and fully automated system would be very expensive.
However, a simple hose with holes in it that you put along your roof ridge, hook up to a tank, and press a button - that would be much simpler. You’d need a couple of hours and some ladders.