Hello,
I confirm that the Google Cloud Platform plugin for Orthanc does compile on UCLouvain's continuous integration server using Microsoft Visual Studio 2015.
I am however unsure of the plans of Osimis regarding including these binaries into their Windows installers:
Furthermore, I highlight the fact that Google doesn't support this free and open-source development, which doesn't favor active work on it. Users like you who pay Google for their cloud services could highlight this situation by getting in touch with Google's representatives (both industrial and scientific partnerships could be envisioned).
Regards,
Sébastien-