1. You do not need to add any oil while cooking since frozen hash browns already have oil in them. I always check the nutrition label and pick a brand that use low oil. 2. You can air fry for a couple of minutes more in case you want them to be darker. 3. I can cook 6 patties at one go in my Philips basket type air fryer, but you can easily cook 3-4 patties at one time too. There wasn’t much of time difference when doing a smaller batch. Just a minute or two less works. 4. If you do not preheat your air fryer, then you will need more time for the first batch.