The source code of the Delphi IDE plugin DDevExtensions is now available on GitHub. There is also a release version for Delphi 10.4. It was not compiled by myself because I don’t have Delphi 10.4. But thanks to the DelphiPraxis fork you can download the release for Delphi 10.4 form GitHub.
All releases for Delphi 2009 – 10.4 are kept on this website for now.