To investigate how the choice of body chemistry affects ligand incorporation, the average ∆⟨λ⟩ of the OE-4mer series was decomposed by repeat unit combination (Figure ). The divergent heatmap is centered at the stability threshold, ∆⟨λ⟩ = 0.11, A and B refer to the 4mer repeat unit pattern (Figure ), and the diagonal contains the data for the homogeneous bodies. The asymmetry of this heatmap illustrates the disproportionate role played by the identity of the first repeat unit in determining stability. For example, furan, thiazole, oxazole, and imidazole repeat units are all less stable as A units than as B units. Bodies composed of combinations of larger repeat units (e.g. fused ring systems) also intuitively have lower average stability. Nevertheless, repeat units like thienopyrroledione, which were selected because their width is larger than the perovskite lattice, still exhibit many stable combinations. Remarkably, all of the explored repeat units are predicted to exhibit at least one combination of linker, side-chain, and co-repeat unit that lead to a synthetically accessible 2D perovskite. These observations illustrate that design rules based solely on comparisons of the ligand and lattice dimensions are overly restrictive and neglect the potential of the ligands to pack through tilt, interdigitation, and alternating patterns.