Simply merged the 3 UIs from the different mods, so they all would have proper inventory icons. I merged the ui_icon_equipment from Original Weapon Renewal 3 v1.0. I merged the ui_icon_equipment from TRX: Upgradable Binoculars + Backpacks. And I merged the ui_icon_equipment from Artefact_Expansion_v1.33 so it would show the new weapons, the new backpack icons, and all the new artifacts as well.
Why then decorated material if it does not work?
Initially I thought it to be working, but realized I was wrong. I've now uploaded the proper files.