Only thing to say is that on a CAVOK day Busselton is a fantastic alternate. It’s 14mins down the road.
It has stairs for both 737, 320, F100 aircraft. The staff their are great. They got all g up and ready 3 times in preparation for Jetstar coming to it. They can handle a diversion. Lack of parking spots would be the only issue if too many turned up.
Nice 45m runway 03/21 with easy RNAVs to follow.
Only thing is if the weather is crap in PH it’s likely to be crap in Busso so KG is the better alternate there.
I’ve being flying recently with East Coast guys and being PH based I do make a habit of mentioning Busselton is now a very suitable airport. Most thank me as they aren’t aware it’s now considered a Network aerodrome. Easy to have missed over the last two years since WA was a seperate country after all and you can easy miss these small but significant things in the mix of all of us getting back in the air.