Difference between “on the fringe” and “on the fringes”

Question

The Longman Dictionary seems to suggest that on the fringes can be used either literally or figuratively, while on the fringe refers to something actually physically away from the center.

on the fringes (of something)

a) not completely belonging to or accepted by a group of people who share the same job, activities etc

a small group on the fringes of the art world

b) (also on the fringe) at the part of something that is farthest from the centre SYN on the edge of something

Nina remained on the fringe of the crowd.

The Free Dictionary, on the other hand, seems to only have an entry for on the fringe and defines it both in literal and figurative usages.

on the fringe

1. Lit. at the outer boundary or edge of something. He doesn't live in the city, just on the fringe.
2. Fig. at the extremes of something, typically political thought. He is way out. His political ideas are really on the fringe.

Any differences? Or is it something that has not reached an orthographic consensus?

Answer 1

They are almost the same but on the fringes only makes sense used figuratively. While on the fringe makes sense both literally and figuratively.

From your example, one could physically be on the fringe of a crowd, or they could be socially on the fringe of a crowd (just barely a part of that group of people). But to say one was on the fringes of a crowd could only mean the latter.