This has been debated before. I can tell you it is not a good idea for several reasons. First it works at reducing radiated heat from the exhaust, but at a cost. The wrap prevents the metal from radiating and shedding heat into the surrounding air. This greatly reduces the lifespan of any metal, be it titanium, stainless or mild steel. Obviously this means replacing the wrapped pipes far sooner than the manufacturer intended, plus the potential cracking issues mentioned before.
Professional race teams have abandoned the use of wrap in favor of ceramic coatings, which are more durable, don't shed, and do not cause premature deterioration of the tubing. Furthermore, NO header manufacturer will honor the warranty if header wrap has been used, and for good reason. See above. I've seen the effects firsthand on my built Ford small block. The headers lasted maybe a year and a half after wrapping. That amounted to about 2500 miles, and included some trackdays and dragstrip runs.
When you factor in the cost of the wrap, ties, and your time, plus the cost of replacing the damaged components, its far more cost effective to send them out and have them ceramic coated.
Thus endeth the sermon.