has been able to grab the mods from steam workshop for Warhammer 3.
To add these mods to your gamepass version of Warhammer 3 you need to:
1. Open the xbox app and navigate to Warhammer 3.
2. click on the 3 dots and click manage.
3. Navigate across to files and click Browse.
4. Once in the file explorer navigate to Warhammer3/content/
5. Once in the content folder create a new folder named "mods"
6. In the mods folder you can either create subfolders to keep you pack files neat or just dump the straight into the mods folder.
7. Enable mods in launcher.
I hope that helps as iv been waiting to have access to mods.