Armor trim item model not functioning as intended

I am trying to add custom materials to be used as armor trim. In this case I am trying to apply a bronze armor trim to my custom sapphire boots from the bronze ingot. The model is working correctly (sapphire with bronze armor trim) but the item model appears as the amethyst armor trim.

I believe this is due to the item_model_index defaulting to 1.0 instead of 1.1 which leads to this issue. Clearly I'm doing this wrong but I'm unsure of how to correctly load the item model for the custom armor trim materials.

Item model:  https://github.com/Leronus/mOres/blob/1.20.1/src/main/resources/assets/mores/models/item/sapphire_boots.json

ModArmorTrimMaterials.java: https://github.com/Leronus/mOres/blob/1.20.1/src/main/java/mod/leronus/mores/item/custom/trims/ModArmorTrimMaterials.java