Where piers are specified, the only window to check them sits between boring and concrete.
Parts of the City of Melton carry fill and variable ground. Where the engineer calls for piers, the depth on the drawing is the figure that has to be reached.
Annotated findings from Bored piers inspections on Melton South builds. Client addresses withheld.

2Slab pre-pourThe day before the pour, with steel, pods and formwork open
3FrameOnce frame and trusses are up and the roof is on, before sarking
4Lock-up (pre-plaster)After roof, cladding and external doors, before plaster
5FixingAfter mouldings, doors and joinery, before the painter
6WaterproofingOnce the membrane is on and cured, before tiling
7Pre-handover (PCI)Roughly a week ahead of practical completionInstant online pricing, or talk to the booking team on 1300 471 805.
Under an hour on a normal residential lot.
Then there is nothing left to inspect.
No, we report against the drawing. The engineer certifies.
No, many are a waffle raft slab.
AS 2870, read together with the drawing for your lot.
Yes, everything is open at that point.