A word of caution about PVC and heat/flame. PVC releases chlorine when it breaks down from heat. That is a very corosive gas that will affect all the metal parts and electronics in your printer. The chlorine also combines with moisture in the air to form hydrochloric acid. I haven't done any tests to see if any chlorine is released at nominal bed temperatures. Hot ends could get hot enough to cause the PVC to break down and cause the chlorine release.

I know the chance is slim but I just wanted to point out the hazard potential here.