I have changed the config to 1.0(100%) for "unique loot chance" for testing how ever I have opened over 100 chests and have yet to find a single unique weapon. I am using a mod pack call "BigChadGuys" and I am wondering if there is some sort of overwrite happening not allowing the weapons to spawn in.

You have to do it from Config Folder -> Simply Swords -> General.config json file . Inside mods config ingame doesnt work