Currently;and have been for years trying to figure out how to datamine these games, if only for the models and environment reference and break downs, especially 3. Sadly, only some models have been ripped through the years, and only the main girls. If anyone has any information or can point me in the right direction, please let me know! 
Hey ! 
I know 2 persons who are good at hacking the Xenosaga PS2 games :
-
Ziron :
https://twitter.com/revampedtele -
Dengarde :
https://twitter.com/Dengarde
You need 3DSMax, and the tools from the Xentax thread, but the models are rippable. Unfortunately the textures are a bit hard to get out(for me anyway) and the UV maps don’t really line up properly with the textures unless you edit them a bit. They do have bones though.
This is Xenosaga III I’m talking about, I don’t know if you can get the models from ep1 or not.
This is still amazing, and more I’ve seen from XS model ripping for a long time!