Visual Studio Cross-Platform CMake - Includes aren't picked up, intellisense is upset about it - c++

Question

I have a C++ project set up something like this:
Linux box:
/home/me/.vs/SomeBigProjectDir
/opt/DependencyOne
/opt/DependencyTwo
Windows:
Local copy of the source
I've set up the cross-platform connection in Visual Studio, and am able to trigger builds on the remote host no problem. However, Intellisense gets upset about #includes - it claims that it can't find any of the included files specified.
Visual Studio has been told to invoke CMake with -DDependencyOne=/opt/DependencyOne and -DDependencyTwo=/opt/DependencyTwo. It's a bit yucky, but we're halfway through migrating off of autotools (these were previously in a configure script), and I don't see how they'd interfere with this. Having these more cleanly packed into some CMake file is an upcoming task.
Sample CMakeLists.txt:
CMAKE_MINIMUM_REQUIRED(3.14)
PROJECT(MyProject)
include_directories(${CMAKE_SOURCE_DIR})
if (DependencyOne)
include_directories(${DependencyOne}/include)
endif()
if (DependencyTwo)
include_directories(${DependencyTwo}/include)
endif()
#blah
add_subdirectory(SubDirOne)
add_subdirectory(SubDirTwo)
#etc
#various targets are declared in subdirectories
The project itself contains many targets, most of which has a dependency on DependencyOne.
If I run a build, Visual Studio happily rsyncs across any file changes, triggers the build on the remote, and it completes without issue. In addition, it has copied back all of the includes to local (on Windows), where they live in \AppData\Local\Microsoft\Linux\HeaderCache\1.0<some numbers>\opt\DependencyOne, for example. So, it clearly knows about them as includes.
Intellisense does not seem to want to believe that these files exist, and I can not find where to tell it to look to find them. Having red squiggles on tons of code that uses these dependencies is just unhelpful, and there is no way to F12 into the header file.
I've tried adding the remote include directories to the remoteCopyAdditionalIncludeDirectories within CMakeSettings.json on Visual Studio to no avail.
I've also tried looking around the internet, but Microsoft helpfully called Visual Studio and Visual Studio Code very similar names, and it's tough to find results specifically for Visual Studio that relate to this type of problem.
Other maybe-relevant information:
Visual Studio 2019 16.9.2
CMake 3.14.6
Red Hat Enterprise Linux 7
Edit:
I re-read through this and thought I could add a little more detail.
To my understanding, in CMake, using include_directories will result in compilers being happy with the following:
include_directories(/opt/dependency/include)
for:
opt
-dependency
--include
---Dep
----SomeHeader.h
----AnotherHeader.h
#include <Dep/SomeHeader.h> //works anywhere that the include_directories() statement applied
In this case, there is that above-mentioned directory living in AppData. The root of the issue is that intellisense doesn't have the sense to look in that directory, despite the project "knowing" that includes are there (it copied the headers over). Because this is a CMake project, there is no CppProperties.json to edit to manually add the paths, at least, not one that I have found.
Edit:
This appears to be a repeat of a bug reported here: https://developercommunity.visualstudio.com/t/Intellisense-in-CMake-setup-does-not-rea/957818. I was quick to judge all headers as causing intellisense to fail - it is only those that have a '.' character in their path. I have reported this to Microsoft.