I've been playing with this weapon mod since its release, and now while playing LWOTC (Long War of the Chosen), I've encountered the problem that the weapons never improve beyond Tier 1. Can you advise what I should do and how to do it, so that I can continue using these weapons further into the campaign?

I tried UpgradeItemsForSchematic and AddItem, but neither worked (though I might have used the wrong ID for AddItem — I only found the weapon IDs in the .ini files, and possibly used incorrect ones).