If Ben is an amateur variations collector he is certainly a high functioning amateur
I personally consider them variations. But given their scarcity and the fact they are on the backs in a set with hundreds of variations and recurring print defects, I can see why they are not more popular with collectors, and hard to find even if you are looking for them. Short of buying large lots or opening lots of packs, neither of which appeal to me, the time and effort of pursuing such scarce back variants is too daunting for me.
Over the years I have ended up with a couple of examples but do not actively pursue them