Perovskite quantum dot (PQD) synthesis often relies on anisotropic growth directed by oleylammonium (OLAM⁺) ions that selectively bind to specific crystal facets. This facet-specific interaction induces a strong correlation between surface chemistry and growth direction, limiting shape control. Lattice incorporation of OLAM⁺ further reinforces this correlation, restricting morphological freedom. We present a nucleophilic strategy that enables early halide release via SN2 reaction at lower activation energy than oleylamine, promoting isotropic nucleation before OLAM⁺-driven anisotropy. This temporal separation between nucleation and passivation relaxes facet-dependent growth, enabling dimensional control. OLAM⁺ then acts as a passive stabilizer, maintaining colloidal integrity without directing shape. This approach provides a general route to morphology-controlled PQDs and achieves stable blue emission through shape-regulated quantum dot formation.