Well, I for one do my Master Skins for Windows 7, 8 and 10, and they look pretty well identical each OS. There is one issue with Windows 10, v1809 right now where the tree (drives) area on the left side of explorer is white regardless of what the skinner set the color to be though. Stardock was informed of this issue quite awhile ago, but they haven't even replied to my email yet. I think it is an issue that will need to be fixed by Neil Banfield, but I am not even sure if he works for Stardock any more as I messaged him too, but he never responded either.
Except for that, and needed to use Start 10 and possibly OldNewExplorer in Windows 10 if you need to, all major areas of Windows 10 will look like the designers screenshots.