Surely that crash showed the "limitations of see and avoid" as per ATSB?
If you are referring to the Moorabbin mid-air collision, CGT did see UPY and was taking avoiding action when they collided. My issue is why a solo student was using the Western Circuit, in days gone the Eastern circuit was used for solos as it had less inbound/outbound/crossing traffic, and the tower always had the ability to bring aircraft inbound via GMH and Academy for an overhead join to the Western circuit if the Eastern circuit was busy. The tower also has a better view of the Eastern circuit for traffic management.
The GMH building is another one. I saw a photo of it the other day on Facebook from back in the day. It was seemingly the only large building for kilometres. Now it’s completely lost in a sea of factories. I haven’t personally used that approach point for years as it heads to the busier circuit, is further to taxi, it backs more onto the training area and it’s entirely over suburbia. So as you say, Carrum is the preferred as it doesn’t have all that, plus it has beach to land on.
GMH as the name suggested was part of the General Motors Holden production facilities, sold in 1997. There were significant, stand out, saw tooth factory buildings, in isolation surrounded by a lot of parked vehicles.
