Enchanting Ethereal items

I have an ethereal Guardian runeword and I can't enchant it with anything, but on the other hand I can enchant ethereal runeword weapons, is there any reason why it's setup this way?

I made this ethereal runeword armor with the intention of adding 2 10% dmg reduction enchants, is it possible to either change the system or swap out the item?

Thanks


P.S. Can you tell me if Scroll of Weapon Upgrade works with Superior/Ethereal items? Can it have sockets? Or does it work exactly like the cube formula?

Enchants, color dyes and orb of alchemy dont work with ehereal armors. That was done to prevent defense bug abuse.
Scroll of weapon upgrade works fine with superior/eth items, all stats will be same.
Example: superior ethereal dimensional blade 15ed/3 ar 5 sockets can be upgraded to ethereal phaseblade 15ed/3 ar 5 sockets

Oh I didn't know there was an exploit that caused it to be this way.

And thanks for explaining that scroll of upgrade is better than cube recipe, I was hoping so!

Still really sucks now I need to make a new Guardian if I want the best survival armor........