That answer in no way resolves the problem of 1) The automatic duplexer not showing up to start with, and 2) the photo tray not showing up at all.
I'm having the exact same issue installing on Windows 10 - the duplexer isn't showing up, the photo tray isn't showing up, and I also don't have the ability to print in color from any normal program (Word, Adobe Acrobat, browsers) as there are no grayscale/color settings in the advanced preferences of the print dialog.
I have followed the above directions twice, as well as the printer properties thing in the orignal question, I've checked settings in the EWS page, and THE ISSUE IS NOT FIXED.
Please figure out a resolution because the printer software as it stands on Sept 21, 2018 has rendered the printer nearly unusable.