Just to confirm, does sigil of major protection work (stack, so masterful crit padding) with iron skin, 122 lore ranks and HCP robes?

Well, I have robes, but with transformation lore ranks (111) (I'm capped) and iron skin I have equal to metal breastplate (torso plate). So would the I'd have masterful crit padded robes or masterful crit padded torso plate ? that's the dilemma.

Thanks anyway Taakooshi

If someone else knows, I'd appreciate it.
I heard it is casted on the character, not the armor, but I'm not sure if iron skin counts...it's a weird mechanic.
I certainly hope so!

Thank you!