Wouldn't travel with the pipe, just be PVC running thru it straight down. No matter since I also was planning just to remove it too and cap it.

Wouldn't I need to do something with the foamboard and put wood to seal it from moisture laden air getting past it, or is that the double duty of the fat head wall sticker. I'd be tempted to just dry wall? Squares into the windows and seal and paint. Trace a faint out line to knock them back out later.

Thanks for that idea, gives me an idea of what to do.

Going to need to play with how far from wall I can put this. Center of the room had some drawbacks but if I can do 2.5 feet or so means I could access back, clean up and maintain wall or windows better etc.