If I could add on, JR wouldn't mind someone who takes on academic comps ie; (AIMO, AMC, ASOC, JSO) and whatnot. Performing in them is a different story but competing in them regardless of results will be a standout. FYI, I received entry into Baulko, NSB and made the interview for Ruse (but chose to personally decline) and I can attest that extracurriculars take you VERY far because everyone is academically competent and you need to stand out --> where extracurriculars are very useful. Please note this doesn't mean that you should just do lots of extracurriculars for short periods --> sometimes it's better to focus on 2-3 in the next year but perform exceptionally in them. For me, these were Sports, Music, Science Projects and Robotics. I understand the desire to "stack" your application but sometimes it's more desirable to let your child enjoy what he is doing. Note this doesn't mean you should limit yourself to 3 activities --> chop and change and then find one that you are passionate about doing. My favourite saying is "a jack of all trades is a master of none, but oftentimes better than a master of one." I split my application into 2-3 sections Academics, Sport, Creative Arts/Music, and Entrepreneurship (optional) which just creates a holistic application.
Onto the Edutest, it just stands as a prerequisite for your application --> perform well in the Edutest = successfully passed the first stage. Please, Please, Please, understand that it is very important to do good in the test --> yes it is pretty much a replication of Selective School Type Testing but note nothing from your application is worth it without a good test result like Blueberry said. It sets up your whole application process. But don't stress it is quite an easy test if you practice the right way --> i agree not to waste your money on the Edutest Practice ones and just go straight to the Vic Selective School Test. Vocab is key so find the TSS spelling list (i think) make an anki on it --> and use spaced repetition for the next year you will easily master your vocab --> find some relevant study methods. Other than that i trust you will perform exceptionally on the test.
Now with the JR thing. Yes, it is an exceptional school. But no it isn't for everyone. You will get stronger scaling in JR as their is no so-called "tail end" meaning your marks will get dragged relatively high --> but internal rankings make or break. For instance, if your child was in Baulko for instance and constantly DUX there would be no logical reason to change schools. His internal rankings would project exceptional marks for the HSC. Note irrespective of the school if you rank 1st throughout --> you get to keep 50% of the highest external mark from the hsc. Meaning i could be at a 400th-ranked school --> rank 1st across the board within the school --> and then get 95+ in everything in the hsc. You "follow your path" but its risky as its up to you. Unlike somewhere like Ruse where the cohort will bring you up meaning a minor slip-up will most likely be saved by a strong cohort. But in reality, i would take any of the Top 3 happily wherein it just come to personal preference. In reality academic competition is similar throughout, Ruse peaking with academics but just consider factors such as sport, co-ed and whatnot when your choosing your schools at that point.
Side Note: nice job Blueberry on Baulko, hope to see you!
Also, Ensure You Have Good Reports!