I also use and love the exact same 49" CRG9, but if you do the 2x retina math, to deliver the pixel pitch Apple customers expect on desktop in the 32:9 display form, that would realistically have to be a 10240x2880 display at a minimum of 60fps. Not sure if there are bandwidth considerations over displayport or similar as this is essentially two 5k Studio Displays (5120x2880) side by side at that point.

I love my CRG9 with MacOS, but there's no escaping the text rendering is significantly poorer than on Apple's own 2x retina stuff.