Fantastic work, and really appreciate the write up. It's quite timely for me - I'm from a tech background and have just started studying Australian law, and was thinking about doing exactly this - so you are years ahead of me :).
Just one note - the link in your Github readme to https://umarbutler.com/open-australian-legal-corpus doesn't seem to go anywhere.
For someone interested in using the data (and help out with bugs/issues), where would you suggest starting?