Additional Years Should Decongest, But DepEd's K+12 Does Not
The main reason why the American Academy of Pediatrics is focusing on the school start time is because of what happens at puberty:
Decongesting the curriculum can definitely add flexibility allowing for less hours required to be inside a classroom. And certainly, this could be achieved by adding years to high school. It defeats the purpose, however, if the two additional years come with additional subjects. Here are sample class schedules for the additional senior high school years of DepEd's K+12:
Unfortunately, the above is only one example from the myriad of wrong things with DepEd's K+12....