No, they are not handled correctly, @Joanna. I just made a series with Z 7+ 14-30/4 and D850 + 14/1.8 + 11/4
So far I can say as long as the height is identical (D850: 8256 / 6880 / 5504×5504 or 3:2 / 5:4 / 1:1), the differences in divergence of the distortion are negligible. But for 6880×4584 and 5408×3600 (DX) it’s a different story. It gets worse when I look at the 14-30/4 Z: Difference from FX to DX is massive. Yes, optical modules were switched on, and I used the trial version of PL6:
▼FX
▼DX
▼FX
▼DX
And as I was already in crashtest-mode, I also wanted to see how C1 deals with their “Manufacturer Profiles” of all lenses. All lenses? No, only the (terribly distorting) 14-30/4 had one, for the 14/1.8 and 11/4 (Sigma and Irix) in front of the D850, there was only a “generic profile”.
▼FX Z7
▼DX Z7
I could add the other two pairs of the 14/1.8 and 11/4, they are pretty straight, even at DX size.
I’m only talking about distortion correction here - every other lens correction I can’t compare (and I also don’t care much about vignetting, and extra sharpening is cheating for me, don’t want over sharpened images), but after this little experiment DxO’s lens profiles lost their glory for me. They are not bad, but none of them was a reason to wait for it or switch to PL. C1 does it better here, sorry. 
I didn’t expect such a difference.