SYSTEM includes in VS

Why doesn't the VS generator not differentiate between "regular" and "system" includes?

I've seen there is an extra CMAKE_VS_SDK_INCLUDE_DIRECTORIES variable which writes to the "VC++ Directories | Include Directories" entry, but I'd have expected that system includes would land there.

From manual tests every project has separate "VC++ Directories | Include Directories" and "Additional Include Directories", so the System and Regular includes could be matched to this.

Is there a problem with that? If not I'd propose that as a feature. Use case is e.g. tooling support (some VS plugins alter behaviour depending on where a header is located at)