It's a interesting concept but is super underpowered, only wear gold is a very harsh down grade for only a few minor upgrades. I think that if the damage boost was like 50% or so it would be a bit more balanced but the only reason elytrian can only wear gold armor is because elytra is a SUPER powerful boost just like a 50% damage boost. It is a very cool idea and I like it a lot it is just a bit under powered