I'm currently reworking GridEx, porting the tool from Godot 3 to Godot 4, with new modeling features and more.
The code for the Godot 3 version of GridEx is available here: https://github.com/BielyDev/GridEx_old
Originally, I wanted to make the code public once it reached version 1.0.0, but I had to pause development for quite some time. The code for the new version will also be released once it reaches version 1.0.0, which will be when it's stable.
Sorry for the delay and lack of updates — see you soon! :D