Hi Hannah,
This is my take on the IITO, memorizing the ITTO is good, it will help you in the exam. PMP questions do not test the memorizing of ITTO, but it focuses on application of ITTO in each process, Knowledge Area, as well as Process Groups. Questions are focused on how PM can use the ITTO, in managing and delivering project deliverable s. what happens if ITTO is missed or not used effectively, as well as using ITTO in decision making. These are some examples of how ITTOs, is tested in PMP exam.
regards
Mani