@Andy ****
I propose that could be up to the officer on the entry point. I have a clear history of no overstays in 8 years. There is also a clear history of me reporting at my wife's address. I have on occasion used a 30 day extension and I've done border runs. I usually only stay 12 nights and go back to work in Oz for 4 weeks, but I have stayed 90 and 120 days. You do you, mate. Good luck and enjoy the Land of Smiles.