Shiny aluminum tape will help a little by reflecting infrared energy off of the  SCAT tubing which would be significant if the SCAT tubing can “see” the red hot exhaust pipes. 

But much of the heating is due to passage of hot air over the tubing which heats the air passing through the SCAT.  A better solution is to wrap SCAT with 1/8 inch thick insulating felt (ceramic high temperature stuff available from Aircraft Spruce for firewalls- cut with scissors and wrap around SCAT and hold with stainless safety wire)  and then slip this through larger diameter SCAT hose to act as a protective cover and to keep fuel and oil from soaking the felt insulation.  You end up with a circular sandwich: SCAT inside of insulation about ¼ inch thick inside of SCAT.  This will go a long way to keeping the third intercooler discharge air from being reheated on its way back to the firewall.  A 10 degree F reduction would be significant in a warm cabin.

Fred