I finally got fully reproducible windows-build with Github actions producing a functional python module for getfem. I could reduce it to only 3 third party dlls (Intel) that have to be distributed together with our pyd module:
for people still stuck on Windows OS you can try the following package (requires python 3.14 and a github account for the download):
https://github.com/getfem/getfem/actions/runs/21790520636/artifacts/5420109841
the build environment and process are fully documented in the github action yaml file
https://github.com/getfem/getfem/blob/master/.github/workflows/windows-build.yml