When I first started reading this forum, the "Folding Bike", to me, was almost always a 20" bike.
My first reaction was, 'look, a stretched BMX bike!'. I quickly learned that was incorrect.
Obviously, there are larger wheeled bikes like 24" and 26" and 700mm bikes.
Then I've seen hints of 'mini bikes' which seem to be 20" versions of the 26" and 700mm MTB and
Which brings me to the classification of your folders.
Shouldn't the large wheeled bikes be called 'folding bikes' and smaller bikes called 'folding mini-bikes'?
Just a thought....