Well the devil's in the details. If you're only putting out half the wattage you will have to install twice as much surface area to get the job done. With silicon panels if any part of it is shaded the whole panel goes down. If a similar situation exists with cigs panels then placing them on vertical walls or doors on the sunny side of a house will always have shade at some some part of the day. I think skyscrapers are one of the few places that application you describe might have some modest success. And then good luck trying to service/replace them. In fact that is the huge problem with any building integrated product easy to access or not.
Elon Musk hires the best in the world. It's silly to think that they have not thought of what we are talking about and I would not bet against them.
And of course Ascent's niche now is with a lightweight application such as is used in space. But there is no volume sales there.
I think our only chance lies with that new scientist they hired coming up with something revolutionary before they run out of money. The problem might be believing him if he does. Especially if he comes up with something just in the nick of time.