Personally, I didn’t bother with Lisa chem at all. I also didn’t bother with any company exams that weren’t strictly made in my year mainly because I didn’t have the time for them.
This was because I did every single VCAA chemistry exam I could get my hands on. There’s a style and creativity that VCAA exam writers have that company exams can only try to imitate. You’ll find a lot of these company exams simply rewrite old VCAA questions. It’s pretty poor quality.
Yes, the old VCAA exams have a lot that isn’t relevant now. I took the time to go through each of them and only printed pages with questions I knew were still relevant. There is still gold to be found in older exams that is worth much more than company exams.
ETA: I treated pre-2013 exams as a worksheet. 2013 and onwards I did the exam in exam conditions but shortened the time to account for questions that weren’t relevant.