I had just been re-reading warforged racial abilities and feats for a possible future character idea, and it stated that the armoured body stuff takes up the body slot, as worn armour normally does. But then I thought about the chahar-aina and the dastana from OA and how they can be worn in addition to armour and specifically stack with it. Obviously the game designers had not taken this into account when they wrote up the warforged, but as written it would appear that both armour additions could be worn by a warforged regardless of which armoured body feat (or the base composite plating) he had.
Composite plating, or the feats which alter it, are not actually worn armour, and therefore the limited list of armours that the dastana and chahar-aina can be worn with does not apply. Especially since neither takes up the body slot.
Now, one could extrapolate the intent behind the chahar-aina and dastana, and given their list of allowed armours are all light, I would say it is reasonable to disallow a warforged with the Adamantine Body feat to wear them. But the rest of the Body feats from RoE count as light armour or no armour, and should be allowed.
