I'm involved with a project using a form of aircrete right now, and we're having a right hell of a time with proper curing and temperatures (to be fair some of that is due to an outrageous spec), as well as mixer truck dwell times, and even input aggregate temperatures. E.G. we had to bring in a refrigerated semi-trailer to store the sand to ensure it was cool enough to make the mix during this heat wave.

We are, in fact, trying to convince the owner to let us put in geofoam in place of the specified aircrete.

It's much, much easier to bring in a trailer of geofoam blocks, place and size them then compared to pouring a lift of concrete and ensuring proper aeration, vibration, temperatures, etc.

Not sure, it’s not been proposed on our projects before. Most likely, that means it’s not cheaper than geofoam or fill.