First off, unless things have changed, they are not polycarbonate, but rather plexiglass. A long time ago, there was a discussion about replacing the smoked material only.....by buying sheets locally.
The debate was whether one could use polycarbonate, or would the bend result in breakage?? A large oven would help, but who has one big enough??
My star cracks have never run, and some are 7 or 8 years old. One of these days, I will procure sheets of plexi and disassemble the frames and replace. Conventional wisdom was that plexi can make the bend with some prudent heat gun help.
"If the women don't find you handsome, they should at least find you handy." - Red Green