Boost install from IfcOpenShell not recognized #8

I used some changes from #7 (props to @johltn) to fix the Visual Studio 2019 build.
Unfortunately the boost library from IFCOPENSHELL_ROOT aren't found even though the BOOST_ROOT and BOOST_LIBRARYDIR both resolve to the correct folders and the files are installed in the library folder. It also recognizes the correct version is 1.74.0 but not the individual components. Error message is: Could NOT find Boost (missing: regex iostreams system filesystem) (found version "1.74.0")
The BOOST_LIBRARYDIR points to the folder containing these files:

Is Boost expecting these files to have a different name, or what else could be causing this?
Please let me know if you need any other information that could help you help me with this issue.
Thank you!