One response is that a comparison need not extend to every characteristic of its implied model. Presenting spring as agent-like with respect to growth does not automatically grant it autonomous power in every respect.
This principle helps keep both analyses disciplined: do not force implications beyond what the indication and context sustain.
Yet that response does not by itself settle the underlying dispute over whether the figurativeness primarily belongs to the predication or to an implicit metaphor and its accompanying features. The theoretical distinction remains.