VSCode IntelliSense `forcedInclude` doesn't work

[programminghoch10]

Hi,
I have this in my platformio.ini:

build_flags =
  -include "include/forcedInclude.hpp"

IntelliSense complains that defines from within this file don't exist,
but a compile succeeds as expected.
Looking at the generated c_cpp_properties.json:

      "forcedInclude": [
        "include/forcedInclude.hpp",
        ""
      ],

I have found this bug,
which made me think the issue is that the cpptools extension isn't able to parse the relative include,
but downgrading that one to before the regression did not resolve the issue.
This however lead me to try an absolute path in c_cpp_properties.json:

      "forcedInclude": [
        "${workspaceFolder}/include/forcedInclude.hpp",
        ""
      ],

which made IntelliSense detect the defines correctly.
During PlatformIO's building IntelliSense index
all other include paths are generated with an absolute path.
Would it be possible to also apply this absolute path to forcedInclude?
This would fix this issue and will make IntelliSense behave correctly & the same as the compiler does.