I am working on a module for upgrading modules to SS4: GitHub - sunnysideup/silverstripe-upgrade_to_silverstripe_4: Tool to help you upgrade your modules to Silverstripe 4. It is intended to complement the amazing work done by Silverstripe: GitHub - silverstripe/silverstripe-upgrader: A tool to help upgrade your code to handle API changes in packages you used..
If you are upgrading SS3 modules then feel free to reach out.