Why should the 'Gap' of a spiral retaining ring be oriented away from the direction of the heaviest load?

Spiral retaining rings are 'multi-turn' (typically 2-turn). While they provide $360$ degrees of contact, the area near the gap is slightly less rigid than the rest of the ring. If a localized, non-uniform axial load is applied directly at the gap, it can cause the ring's end to 'lift' or unseat. In applications where the load is not perfectly uniform (e.g., a splined shaft), orienting the gap to a 'low-load' zone ensures maximum stability. Furthermore, in centrifugal applications, the gap should be positioned to avoid any potential 'unwinding' moment caused by the rotational acceleration of the ring ends.