While I would not use PVC for a dryer vent, I would not lose any sleep over it's use, the temperature of the exhaust air from the dryer is well under the maximum temperature the pipe can withstand. Just for the record, galvy sheet metal duct is preferred by me.
To expand some more on your post above... anytime I read where someone has mentioned something in their project that could be a hazard... and for sure one that can become a FIRE hazard, I feel I have the responsibility of mentioning it. Just as you do over on the L/E forum...
As to not derail the OP's topic though, while listing the negatives of using PVC pipe on dryer ducts here... it would probably be best for the OP to just do an internet search and see for himself about why PVC should not be used for dryer venting, if he chooses to do so..
Plenty of info on this topic out on the WEB including the DIY Chatroom forum and You tube videos. Including the building codes standards listed in IRC M1502 -4 which does not include PVC as a suitable dryer duct. He just needs to type in his browser, " PVC pipe for dryer vent" JMO