... under GNU GPL v3 (https://www.gnu.org/licenses/gpl-3.0.txt). I am not aware of any adverse effects. However, use it at your own risk!
Subscribe to the mailing list: https://sourceforge.net/projects/wsjt-x-improved/lists/wsjt-x-improved-community.
If you want more, also take a look at my new jtdx_improved project (https://sourceforge.net/projects/jtdx-improved/).