Re: drill spacing I am no expert, so these are just ideas, but...

Re: drill spacing
I am no expert, so these are just ideas, but orogenic gold is generally associated in areas adjacent to fault/shear zones and/or related vein networks (i.e. Mertondale Shear Zone).
The gold can be within the Qtz-rich veins or in the hydrothermally altered halo and can be patchy depending on the depositional mechanism (wall-rock interaction, effervescence or fluid mixing). For example, an assay in one area may be X ppm, and upon mining, the grade proximal to the original drill hole has been known to vary by 1000%.
Small spacing is likely being used to better understand the resource present due to the variability of mineralisation.

A geo with orogenic Au experience could probably clarify if the drill-spacing can be justified due to the nature of the mineralisation in the area.