Ok guys, I made some progress on modding XXL.
Now I know the format of all the KWN/KGC/KP2/... files well, especially for the first XXL.
I wrote some format specs here: https://github.com/AdrienTD/elbtools/blob/master/docs/kwn_xxl1.txt
And I also started developing on a editor in Python, named "PyKEdit"
It is possible to replace the textures IN ANY SIZE
That means HD textures are now possible on PC
I can help you in the UI if you want so you can see how the program can look like to be more user friendly
Will the program include sound export/import, text changer, texture export/import in one program?
As you can see at the left of the window
You can select a specific chunk of the data in the file
For example here you can also see geometry
I can work on some design tomorrow for you for a user friendly workspace
If you want, but there's no real need right now