Yes it's common practice to just drill one hole when testing a...

Yes it's common practice to just drill one hole when testing a well-defined target i.e. common in nickel exploration where you are testing a EM conductor - it's either nickel sulphides or it's not e.g. barren Fe sulphides or graphite.

Same probably goes for this case i.e. it's either spodumene-bearing pegmatite or it's not. Though this target is less-well defined as it's based on geochemistry in a highly weathered terrane.