Fair enough. I asked for where there might be a gap; mahasamatman identified one possibility (though that struck me as an instance where pre-boarding is being used for pre-access to justifiable needed overhead space rather than for actual extra time needed).

FT is very good at identifying corner cases; I maintain, however, that in the majority of instances of legitimate disabilities requiring additional time to board that disability is likely to be an appropriate disqualifier for exit row seating.