gpg4win builds gnupg + a bunch of other things (such as a complete kde stack for kleopatra), with the mms-bitfield flag. All of this is crosscompiled on linux, instead of natively built on windows.
We can either copy the binaries from gpg4win, and then rebuild our complete stack with the mms-bitfield flag on top of that, or we find a way to build gnupg on windows without the mms-bitfield flag.
I suggest we try to build gnupg first (everything else we have already)