There have been numerous articles in the SMH and The Age recently about medical cannabis which I would recommend reading.
A brief summary is that Australian Law hasn’t kept up once again with the changing landscape. So whilst medical marijuna is legal, of which you can get in CBD form or THC, it is still illegal to drive under the influence.
Now whilst most medical experts agree that the the “intoxication” lasts about 3-10hrs dependent on dose you can actually still provide a positive roadside test for drugs sometimes up to 4 days later, as all it tests for is if there is a drug present.
Advocates for medical cannabis are asking for an overhaul of the current testing regime as you can be driving around on high dose opioids but can’t drive around with cannabis in your system.
A major shift towards determining an acceptable amount of THC is needed.
So until this happens I’d stay clear as you are unfortunately only opening yourself up to a major can of worms