my Unity external annotations don't work anymore with 2017.3

In the past I had manually setup a UnityEngine.ExternalAnnotations.xml file, with various things like marking Debug.LogFormat() with StringFormatMethodAttribute, etc.

However that doesn't work anymore, I believe this broke when I upgraded from 2017.1 to 2017.3. I also upgraded VSTU to the latest version, which now doesn't use the Library/UnityAssemblies folder but links to the Unity install directly.

I saw now the Unity assemblies were modularized, I made UnityEngine.CoreModule.ExternalAnnotations.xml file in the proper directory, but it seems R# is not picking it up. My UnityEditor annotations still work. Any idea why it broke?

And I know, I should probably be using the extension, but I would like to make sure I can still do my own setup and tweak it to perfection :).