That's a good write up of the differences in the 3 basic types. It would have been nice if they had included a little info or some reference to the variations, such as the Oxygen Barrier versions and the PEX-AL-PEX.
They do carry them and do say this about them elsewhere.
"Oxygen Barrier type PEX tubing is designed for use in
closed-loop applications, including radiant heating and hydronic
heating systems, which contain ferrous (cast iron) components,
such as circulator pumps, radiators, boiler heating elements and
others."
Additionally, that the PEX-AL-PEX is, "Tested and Certified by NSF for potable water applications and complies with NSF/ANSI 61 standard."