Another rescue from my pool, NW Tucson area, 3400' elevation. DLS is about 1.5 inches. At first I thought it was "just" a juvenile A Chalcodes, but after watching it for a while and looking at pics, seems to be much more mature and doesn't resemble what a Chalcodes should look like at that size.
I have a New River chalcodes exactly the same size as your sling. Similar in body, identical abdomen--but its carapace is more golden, and its legs are tan from the feet to three digits up the leg structure on all legs, unlike your sling. I don't believe it's a chalcodes you have there.