The mnmlstc/core library (when enabled/configured as the polyfill library to use) is prematurely installed to the install prefix of the CXX Driver during the build step as part of custom ExternalProject_Add() step to patch include directives in the library.

There are several points of improvement to be made:

• Avoid the need to patch mnmlstc/core by using proper CMake include directory paths (build vs. install interfaces).
• Use FetchContent instead of ExternalProject to move the download-and-build step into the CXX Driver's CMake configuration step (idiomatic/modern CMake).
• Avoid premature installation to the install prefix by using a local install directory within the binary directory instead.