Suppose they played some video games after each hour study period. Then given the relaxation and happiness it entails, getting back to study would require a good amount of self control. Self control is limited, so why waste this supply of self control on reverting back to study every hour? You end up getting burnt out by this.I suggested these things because a lot of teens like playing video games so why can't people use this as an outlet for a little bit of fun while they are studying? Doing 4-5 hours of study a day is more than sufficient at this time of the HSC. What you are suggesting with 5-10 minute breaks is studying like 8 hours a day which is too much I would say considering you have 6-7 weeks of holidays. I don't get your whole point about short attention spans and losing focus, you are just stereotyping all teenagers as being mindless and not being able to control themselves after they see a meme. If someone really cared about their atar I'm sure they would have some self control and actually get to work. That's why in my last line I said you must be focused in that 1 hour time. Is it better to do 8 hours of work with only 5 minute breaks where you become sluggish by the end of the day, or to be fully focused for 4-5 hours and still maintain your sanity and mind during those 6 weeks.
Why does the person have to study 8 hours a day? They could study for 4-5 as you've suggested, just shorter breaks so the transition from break-to-study is easier.
Most teenagers possess short attention spans. I think that I'm wrong here but it feels that teens are significantly more impulsive than adults which is the basis of that point. About meme, I don't know, but for youtube: due to it's diversity and convenience, it can easily pull you in after 1-2 videos ('just one more'). There are people who actually cared for their ATAR but cannot control themselves to study.
My whole argument is on the basis that you should, on average, stay at high concentration levels while in that study block of 4-5 hours. I think in that way, it's hard for you to get distracted and you get your work done quicker (since shorter breaks). Then consider entertainment options after this. I guess you can play and work simultaneously...