Mike, remember "Tick" Richardson and the shop he built west of Oblong now occupied by Dependable Electric?
I had considered PVC for airline before seeing his runs in that shop.  The PVC had overheated, drooping between fasteners because of wood stoves heating the building. I asked his employee about the drooping plastic pipe, nobody seemed to be concerned.   When I realized how easy it was to bend, I figured it would also be easy to break.  Funny, they kept using the line, I don't know if it has been replaced now or not, haven't been in the shop for some time.
I had never thought about physical damage if it blew, just didn't want to repair it, so I used pipe in my shop.