To me, a sharp-edged crease in leather means uneven wear across the surface. Leatherique will soften the edges, so to speak, and keep the crease from worsening (in the cases I've seen).
Use it several times, and leave it out in hot sun for several days if possible. I've found that three soak & rinse (Leatherique, then Prestine) will help. By the time the L is standing on the surface, you've done what you can.
Be aware that some leather is plastic coated from factory. I've found that a good cleaner will remove this on worn leather (DAIMLERChrysler, two vehicles), and the the L will soak in.