So, what I don’t understand is why NASA doesn’t make this really simple — allow SpaceX to use the “load-and-go” process on flights that don’t involve putting living beings into space, and when they have repeatedly and sufficiently proven how safe the system is, then start talking about whether or not it could be used to launch humans.
Don’t even talk about using the potentially more dangerous system until it has enough of a safety record.
SpaceX has been using supercooled propellants (and "load-and-go") for every launch since early 2016, including NASA cargo launches. It's been used over thirty times by now. Whatever additional assurance that NASA's advisory board wants, another few launches are unlikely to provide it.
Don’t even talk about using the potentially more dangerous system until it has enough of a safety record.