Pearce 18/36 8000ft RAF still struggling with metric concepts
I work App Dep so I can only speculate delays. We catch them as fast as the tower can fling them subject to the 10nm same sid/route that Melbourne centre requires but I suspect that the quantity of aircraft, the mix of aircraft (jet prop), the sids being designed for when the RAAF are active, one runway (I think on the day in question 06 was the only nominated dep runway) and the fact that the airport is at best a 1950s concept of what an airport should look like (I mean specifically the rwy twy design).
If the taxy slot times aren’t working you need to talk to the tower. Airservices has secretaries available to take these details. Ring the tower and ask for the ALM they’ll know who you mean. If the airport infrastructure is stuffed tell Westralia Airports.
The controllers are pedalling as fast as they can and at time faster than they should, while working for a very ordinary company.