Andrew sometimes comments that ecological psychology has moved along, in some respects, since Gibson. And Chemero argues that for a diversity of interpretations of affordances. (Chemero manuscript here.) Actually, the other papers in that issue of Ecological Psychology probably attest to a diversity of opinion as well.
So, once we get to the point where we recognize that Ecological Psychology is not a single, monolithic body of theory, we can move on to spelling out the differences. And, some of those differences might concern how physical and geometrical quantities are to be used, or not, in Ecological Psychology.