Iirc, JP likes to coat the mani and hotside, but only do the dp if its close to things that can melt. Heatwrap does tend to fall apart after a few months so thats why we dont use it.

You cant really wrap a mani or the hotside easily.
 
It can last longer if held on well. I've heatwrapped my down pipe and its still on ok, and thats been well over a year. I've put lockwire on it and twisted it tight about every two inches along on the downpipe, much better than the steel tiewraps.