Much as I sympathise with trying to reduce local charging, this really is a problem for me.
I rarely use the supercharger to save money. I had the $1/day unlimited AGL plan for a while, and now pay just 13c/kWh off peak, so about $8 for a full battery. I'd be mad to sit there for an hour to save a few bucks.
But, in my line of work I'm frequently required to drop what I'm doing and head out of Sydney (eg. Canberra, Newcastle).
In these situations I sometimes am caught short and need to go to the supercharger before I start the journey. The slow supercharging has been a nuisance in these situations.
The Central Coast SC is a boon for the Newcastle trips; if I have 25% or more I can just head north and drop in there. But Canberra is a different story, I need a good 70% to make it to Goulburn, and a few times I've been at 40% and it's taken over 30 minutes to get to 70% at St Leonards.