What's been wavied in your Owens Corning Warranty
Everyone needs to contact owens corning and check to see if this Platinum Preferred Contractor got the Owens Corning to issue a "wavier of requirements" for the installation of the shingles, the new drip end, the new step flashing.
Spoke to Owens Corning Technical Roofing Specialist 'Mel' and he explained that Owens Corning does waive warranty requirements if the Roofing Contractor makes a requests. He went on to say this is intended to be transparent to the homeowner, i.e., not supposed to find out. Which means you need to contact Owens Corning Headquarters to see what your warranty really covers, before you have an issue.