headers often crack with or without wraps depending on climate. ive wrapped my modded up stock cast mani and left my tube headers unwrapped.
shields to contain or reflect excessive heat are massively effective. something in the order of 60% containment or 95% reflection of radiant heat on the nearby components if memory serves. a huge step up from ceramic coatings suspect effectiveness and claims imo.
a simple alloy shield facing the headers helps the wires in the vicinity from being cooked (i think some stock alfetta alternators and around the MC reservoirs had these)
many years ago i locally wrapped 5-6 inch section of brake line on my 105 gtv that went over the exhaust in the tunnel area which cured my boiling problem at turn 3A that would force me to use the run off escape route.
shields are simple, lightweight, effective, adaptable, low cost and reversible which is important given the rising values!
all modern cars run with an abundance of shields with the need to heat up the cats quickly for emissions while protecting merit of electrical components that are heat sensitive in a densely pack engine bay.
in addition to simple alloy sheets or barriers, they also have a pliable sandwich multi-layer constitution sheets with thin silvery reflective skin layer to form around complex shapes and retain their shape memory. Grassroots racers hit the junkyards that are filled with these wonderful advanced heat barriers.