When you get into "storable pools" a whole lot of what we know about pools goes away.
(including the receptacle you are asking about)
It certainly calls into question all of the "fastened in place" language.
I think a storable pool only requires GFCI for everything and listed equipment, along with the separation/clearances in 680 part I.
As an aside, I have one of those 1/3hp storable pool pumps and it is a tiny little motor. I just bought it because it was cheap on Ebay. I was thinking about using it for solar heat experiments.
