Assuming that we are talking about routine EST, surely the "practical approach" is to ignore it altogether? As Mike has mentioned, if the kit sails through the other (current leakage) tests, how can there be a problem with "touch current" (enclosure leakage)?
Unless, as I say, you are looking at some other definition (that we are not aware of).
Unhelpful phraseology like "representative sample" can only be dealt with by making a note where (if, and when) you ever
do find a "touch current" worth recording (that is, the reading that has traditionally been known as "the worse case"). And (again as Mike has said) it's up to the tech carrying out the test to decide how much time it's worth spending hunting here, there and everywhere. Just the carrying handle, the front panel, and (or) anywhere else that appears obvious, for Goodness Sake!
But I concede the point that your opening post should have warded off any discussion of (relative merits of) the various measurement methods available under IEC-62353, as it clearly states
"touch current shall be measured with the equipment powered from a supply with an earthed neutral". That's why the conversation was moved to another thread.