Hello, I use Customizable Player Models and usually I set my models to have invisible armor as to avoid meshing, however I noticed that the armor sets added by this mod specifically still appear visible and I'm assuming it's because it could possibly be lacking the proper tag for armor, but I have no way to be certain...

Can you specify what exactly should be done in technical terms?

Well, I don't know. I'm not knowledged in modding, I can only tell that something is causing the armors from this mod to render differently to vanilla armor. MC Dungeons armor for example also adds a lot of variating sets that still go invisible when avatar customisation mods have that option enabled, but the same isn't happening with this mod and other Spell Engine addons

The difference comes from being these armors being rendered in a completely different method.
MCDA uses vanilla armor renderer.
Paladins & Priests uses AzureLib Armor renderer (GeckoLib armor format).
I don't think there is anything I can do, I recommend reaching out to them.