I attended a nice presentation of two PTO2 vehicles tonight. I asked exactly one question and it has been the one you mentioned.
I was told that the rear seats are fixed with 13 bolts that are unscrewed quite fast. The fixings to put a commercial into a SW setup would be there and not closed by welding something over.
Of course many things will be separate when we see the first customers cars. But at least I got this information now.