Thanks to the collaboration of Jernej Jakob the script has been rewritten. We're calling people for testing this new rewrite before we publish it as a release.
The new version is currently in a separate branch on Github. If you use this script and need to deploy a new cert, we kindly ask you to test the new version and report back if you encounter issues, and even if you don't! So we can know it works fine.
Istructions are on Github:
https://github.com/YetOpen/certbot-zimb ... or-testing
Thanks everyone