This is a modification which increases the efficiency with which the plants generate needed sugars which presumably are used everywhere in the plant, not just t

This is a modification which increases the efficiency with which the plants generate needed sugars which presumably are used everywhere in the plant, not just the leaves. Why would this only increase the size of leaves? Indeed, if each photosynthesizing leaf becomes more efficient, wouldn't this decrease the number of leaves you need to support the non-leaf consumable part of the plant, allowing foliage to decrease?