Shaun in his last interview stated the Decline is just about to exit the middle aquifer. That is the middle sandstone 25m thick.
The next layer is siltstone 35m thick this is slightly harder and better for the drill and blast development
The hardness dictates how far in they can drill and blast before there is any danger of the roof falling in.
Looks like that middle aquifer they were doing just under 3m per day, this next layer may increase to 4-5m.
The Lower Tillite /aquifer 95m thick is a very strong strata this will mean they can go further with the drilling and blasting maybe 8+m per day it will accelerate .
There is a formula they use I think it’s to do with the height in that they can’t drill and blast more than the max height, so that’s 6.5m.
I would say that is a minimum to expect and more if they can advance that in one shift, so I would expect one and a half advances per day