The dev of the GUI hasn't been on Github in 3 years, they are not going to update or add any features.
I see someone made a fork in the past few months and wanted to point to it as they seem to be implementing some fixes requested. Hopefully they are able to do more but at this point we may need someone to make a fork that will be updated or feel free to list her alternative for users to use.
https://github.com/Zulux91/namDHC/releases
Here is a fork that has a couple of fixes if you do like this tool.