I think a lot of the more sorted folks are also using frozen brood tests. Prof Ratneiks at Sussex lays out the basis on a slide
It was demonstrated a while back that general hygienic behaviour as demonstrated by the frozen brood test is unrelated to VSH.

This quote is from Jerry Bromenshenk:

I invented the liquid nitrogen freeze method while working on a project for
EPA. I found that neither the pin prick nor Steve Tabor's - cut and
freeze in freezer- produced consistent results. The problem is that physical
damage (pricking, cutting out bits of comb) can induce a repair behavior.
Hygenic behavior is supposedly controlled by two genes, each with a bit
different behavior. Also, removal of paper is probably not a good test -
its just part of a two step process.

As per area of brood - the larger the area you kill, the more certain you
will be to see bees take action - that's again not simply hygienic
behavior, but a response to a damage 'crisis'.

What most have forgotten - our data showed that several small patches over
more than on brood frame provided the most reliable test.
Jeff Harris noted that VSH bees do not uncap freeze killed brood any better than run of the mill bees.