Remove it.  The cylinder heads can handle high  temperatures and are  flooded by a flow of high velocity cooling air.  The pipes face downward so the cylinder heads do not "see" much thermal radiation from the pipes.  The heat removal from the air blast through the fins dwarfs what thermal energy the exhaust pipes can deliver. 

 

"Most of the ones i've seen are concentric to the pipe....which seems like a bad idea."

 

It is.  It makes for local hot zones on the exhaust pipes, and you know what that means.  Slow motion bubble gum. See again Brent's highly educational picture of his cross over tube after it had been wrapped. 

 

Localized reflectors protecting rubber shock mounts or engine mount pipes that are very close to exhaust pipes are fine and help extend lifetime of these items.  The most temperature sensitive stuff is made of non-metal: wire insulation, hoses, composite cowls, etc.  These may need protection, and if so should be individually shielded by wrapping or covering them with a reflective fabric like the aluminized Zetex fabric mentioned in years past.  You can also  get similar materials from race car suppliers.  Clark Baker put me on to Thermal Control Products http://thermalcontrolproducts.com/home.php  They make blankets, tube wraps, etc.  Have a look.

 

The photo attached shows  Zetex fabric wrapped around the engine mount tubes.  The upper wrap also protects wiring.   One wrap shows attachment via cable ties which I did only because it was farther away from the exhaust pipe, and because I was out of stainless wire.  Cable ties age quickly when hot.   Use wire instead. 

 

F