And it has to be an international departure (at least for those in the USA) as domestic first class awards don't get you into the *A lounges.

Of course the same would be true if you paid for a first class ticket. I would be really pissed if I spent $8k on a LH F/cl ticket to Austin only to find out that on the UA codeshare leg I do not have the right to enter a lounge. What a surefire way to lose F/cl customers.