At this point, I don't think SRK's update on Hay Mountain is needed to begin drilling, but when available I'm sure their report will suggest the breadth of the next step.
Looking back, the program at Big Chunk in 2012 was to have been 10 holes had it not been cut short by an early winter (and subsequent litigation). Beyond that, I think 10 holes is pretty much standard for these structural conditions. Once the drills are mobilzed, it really doesn't cost that much more for 10 holes than for, say, three.
News soon, I'm sure.
VP