Ah, I guessed that; that's why people say using it is illegal.
Well... it's surely on my long-term plan... I thought I go with some of the utilities you linked in the first post; but I fear they might just be missing some things (especially since the author claims "I just made it to work with the textures I needed, might break with others"); though they are a great starting help.
There are also a lot of weird vertex attribute formats in the vertex buffers noone nicely / more completely documented; my add-on doesn't support all yet. You can find those supported
around here, but if anyone has more information on them, they're welcome!