no stock lending, page-14

Dull,
I don't understand why categorising these types of transactions as professional or not is important.
Any system that allows players to profit while breaking the rules is open to gaming - one just needs to do a cost/benefit analysis. Environmental law is rife with examples where it is cheaper to pay fines that clean up a mess.
IMO, and I'm confident you'd agree, T+3 should mean T+3. Clearly, that is expectation of most small investors and indeed most market players. I imagine that most people would be surprised that you are not forced to close a short position on T+3.
As the article states, the ASX could fairly easily amend the regulations.