Rhino's Iron Skin is heavier than it should be

[Zurion]

Recently (I think it started with U18), Rhino is not affected by the "lifting stream of water" in the void (I don't know what to call it). Basically, it's this one.
 Also, the stream that pushes you down (also present in this room, but on the opposite side) will not have any effect on a Rhino that has Iron Skin active. 

The streams do affect a Rhino whitout Iron Skin active.

The streams can be found in the big room with a tree growing from the middle of it, in two secret rooms and in the one where three paths converge (picture below), where both the up and down streams are present.

My guess is that Iron Skin now uses lead, which is a lot heavier. Can I suggest a different metal that's stronger than lead/iron and at the same time lighter? Vibranium would do perfectly, but since it's pretty hard to come by Vibraniun, Adamantium would do just as well.

[Kainosh]

P-P-P- P - P - P - POWER!

[Zurion]

I just found out that Iron Skin also gives "immunity" against the air current in the bottom trench of the orokin derelict secret room.

But it's no longer as potent against shockwaves in sortie missions. Although I won't be knocked down by Shocwave Moa's or the Bombards/Heavy Gunners, I will still be pushed back.This might be intended, but I didn't see it in any patch notes.