VS: 16.9 ambiguity between VC toolsets 14.28.29333 and 14.28.29910
Visual Studio 16.9.x is shipped with several C++ toolsets including 14.28.29333 (16.8.x milestone) 14.28.29910 (latest, 16.9.x). Both have version number starting with 14.28.
CMake does not recognize three-number version in CMAKE_GENERATOR_TOOLSET. E.g,
Two-number version 14.28 is treated in favor of latest toolset making 14.28.29333 inaccessible.