Outlet is not a true MIP. same thread pitch and diameter. It's not tapered and not meant to screw on a female pipe fitting. made for supply hoses or a slip joint tube but nobody uses the later any longer.
A lot of faucets these days come with 3/8 compression on pre attached supplies. why not use an angle stop with 3/8 comp outlet and get a supply hose 3/8comp X 1/2 fip?
There are some stops that have 1/2 O.D. comp outlets.
Not what you looking for!!