Perhaps I should have provided the maths. Typical track with 100m radius and track width available of 16m, therefore outer markers at 108m radius.
Ignoring straights,
1 Lap of a circle with 100m radius = 628m
1 Lap of circle with 108m radius = 678m. That's 50m extra the outer horses run in one lap. I can't see too many conflicts at crossover with that advantage.