may be able to write a utility or at least give you a guide to do it manually. Could you upload an example file and link it?
Oh, that would be very helpful!
This is the .xpps file (Since I am an Internet stranger, I would expect you to check this file at your own risk.)
https://mega.nz/file/xiIHDSyI#EUTY6vQUweqyNWGX9JpcG1hDHdW4pgKI8DHYxa1NMys
I am new to extracting files by reading the hex code and stuff, so I don't understand how to work with it. But from what I can see on some threads online, people have attempted to do the same, thought I could not understand the conclusion they reached.
Here is the thread on upacking the .xpps files I found -
https://reshax.com/topic/759-ghost-of-tsushima-directors-cut-pc-version-xpps-xmesh/
also
https://reshax.com/search/?q=.xpps&quick=1&type=forums_topic&item=759