I'm in year 11 studying EI at CHES and highly recommend it!!
The subject itself requires so much discipline because it's essentially all you - you've got to manage everything and are basically given free range to research whatever you want. Personally, I enjoy studying externally however it can be VERY easy to put off work (eg, reading 12 reports is just going to keep happening 'later'). However at the same time it is super rewarding and I think will be really useful for university or even just later in life. Not only do you write a report, but you also have to think critically about ideas and the media - a very useful skill to have!
The way it is structured is that you have a 1 1/2 hour class, this year it is Wednesday evening 4:30 - 6pm. This is like a normal class at school where you can either join online or in person. Then you have one tutorial during the week of around 4-6 students, this usually goes for half an hour and is online (although as a student you've kind of given access to the building whenever it is open - massive perk). The rest of the time you're expected to be completing either a given task or (mostly) whatever work you've set yourself that is relevant to the research. The teacher is always available (they have timetables showing availability), so if you need to have a quick web call to iron out an issue you can usually do that within the day. It operates through teams so you can send a message through the chat - my teacher honestly usually gets back to me within like 20 minutes usually!
As far as the environment goes, it's lovely. The teacher is superrrr supportive and (for my cohort at least) you end up getting relatively close relatively quickly. It's a nice community and the best experience.
Bottom Line: DO IT!! 🙂 And let me know if you have anything specific you want answered. Good Luck in VCE!