Here's the ceramic coating warranty from the TTI site. There is no direct recommendation of using another exhaust system for break-in prior to installing their headers but they also state that recoating them would not be covered if it "shows evidence of the use of insulating wrap products or shows evidence of adverse conditions such as high heat temperatures encountered during engine break-in or if used in any racing activity." Otherwise, according to the warranty, discoloring would be covered 90 days from the date of purchase. Granted, you would still have to pull them off, send them back and then reinstall them. Here's the exact verbage:
CERAMIC COATING WARRANTY: TTI warrants Ceramic Coated Headers to the original purchaser, to be free from defects in material and workmanship for 90-days from the date of purchase. In the event of an alleged defect in the coating (peeling, discoloring or rusting), TTI’s sole responsibility is strictly to have the headers re-coated at no charge. Under no circumstances will TTI re-coat any header that shows evidence of the use of insulating wrap products or shows evidence of adverse conditions such as high heat temperatures encountered during engine break-in or if used in any racing activity. TTI will not warranty cost of removal or re-installation of the headers, loss of time, inconvenience or other incidental damages. You must pay all shipping charges incurred unless the headers were purchased within 90-days of warranty claim. Within the 90-day warranty, TTI will assume responsibility for return shipping charges.