So are we to assume it won't be possible to leave her in this position for long without risking damage?
Possibly but looking at that FB vid..the body is made to fluently articulate in dynamic poses like this..you just can't keep it that way for long time periods but imo the relief comes from that the joints move so naturally without any awkwardness.in my experience with handling phicen seamless is the durability when posing, not only is silicon skin powdery to the touch, it is also gives a vibe that extreme posing will break the metal skeleton underneath and the outer skin will tear quicker.
This body seems like all the joints move more fluently