The difference in heel-toe height is traditionally 12-14mm.
This means the majority of cushion is under the heel.
Which encourages runners to land where most cushion is.
The consequence is overextention of stride, and crash landing on heel. Cadence falls to 120-140.
By reducing that heel-toe drop, it may encourage the feet to land more evenly.
Typically this will often lead to a shorter stride, where the body's center of gravity is more centered over the feet.
Biomechanically, this *MAY* be more efficent for distance running. But it is also very possible heel or forefoot striking may be better - think of sprinting; you'll be on your toe.
Finally, take into account the need for cushion on concrete/sidewalks. and the need to SLOWLy transition to zero drop or lower profile shoes.
Additionally, heel strikes are often associated with knee problems. FOrefoot striking may lead to lower leg injuries. So it may just shift where you injured around.