I just wrapped my stock manifold instead,does a real good job in keeping under bonnet temps down imo.
With a wrapped manifold i dont think there would be much if any benifit to wrapping the hot pipe aswell?
There maybe a possibilty of the cast manifold cracking due to this though,especially if ported,but tbh i dont think i have ever heared of a gtir manifold cracking?
Have also read about heat soak back into the head doing bad things with wrapped manifolds/turbos and down pipes etc,so i only wrapped the manifold and left the downpipe and turbo free.
On the plus side the now hotter exhaust gasses are ment to travel through the turbo faster and are ment to help improve the spool up speed,not that you will actually notice it lol.
If there are any adverse effects to the turbo with a wrapped manifold i do not know,maybe more likely to crack around the wastegate port?