From what I understand with the retina display the screen is always in native res (2880 x 1800) but treats it as a lower res. The highest the system allows is 1920 x 1200, using the higher resolution to display fonts and interface elements at the higher resolution. So I guess the system is always using resolution scaling of sorts.
I was not using any third party software to scale. The 32 bit client went all the way to 2880 x 1800 not matter what resolution I was in. I noticed recently the 64 bit client will only go as high as the selected resolution at launch and since the highest normally selectable is 1920 x 1200, and that is the res I usually use outside of games, that was the max allowed in the game. If I lowered it before launching the game I would be restricted even lower.
So after discovering that I tried a third party app that allows you to select higher resolutions, up to the full native 2880 x 1800, which is really hard to see on my Mac book. After launching the game in this mode the higher resolutions were available in game. So it seems the game will always see the current resolution as the highest available resolution.
I will try reinstalling at some point, but that is several hours and it's a drag on the system and network even in the background.
Thank you.