In this work, we employ a high-throughput automated experimental workflow to effectively explore the chemical space associated with phase complexities, including phase emergence behaviors, in quasi-2D HP films , defined by the spacer cations Here, five primitive 2D HP systems employing spacer molecules with distinctive physicochemical properties are selected: n-butylammonium (BA), butane-1,4-diammonium (BDA), thiopheneethylammonium (ThEA), and 3,3diphenylpropylammonium (DPA), respectively; these cations represent key aspects in the chemical space -including molecular sizes, shapes, molecular weights and dipole moments -of the molecules. By combinatorial mixing them with 3D CsPbI3, the spacer-dependent phase emergence behaviors and stability of the low-temperature (<100 o C) processed film matrices are systematically assessed.