Changing Window Title and Icon
Yes, you can do that with KubeJS too.
To change title, all you have to do is change
To change icon, you create a
kubejs/config/packicon.png image in standard Minecraft texture size preferably (64x64, 128x128, 256x256, that kind of size).
The image has to be saved as 32-bit PNG, not Auto-detect/24-bit, otherwise you will get a JVM crash!
Here's how to do that in PaintNET: