Ever since we migrated GpgME++ and QGpgME its been a problem that these two binaries from Gpg4win don't integrate with MSVC Software.
We need this now at least to support GPGME integration in the AppStore MSVC build of Okular.
With the change to signed / encrypted attachments this was apparently also an added problem for Applications using these libraries.
Libreoffice has its own build system and some patches https://github.com/LibreOffice/core/tree/master/external/gpgmepp
I think Craft or at least @dvratil had some patches too to add a CMake build system on it. We could probably also life with a static Makefile.MSVC or something like that.
We would maintain the autotools build system of course, too and use that for our releases as it is important for us that our Software is built with Open Source tools.
Ingo you also mentioned interest in this, from sune I know that he currently has a craft setup for building so maybe sune would be the closest one to take this up?