We We would like to note that deriving B by using the same pressure range for each compound results in the same trend but with a slightly larger 𝜎B. Across the here investigated series of compounds, we find a correlation between Ap and B (Fig. ). The more distorted the framework is at p = ambient, the stiffer it is (Table ). Since framework distortions summarised in Ap are some of the lowest-energy pathways for pressure-induced structural changes, a smaller Ap provides a larger margin for pressure-induced network distortions as a response to hydrostatic pressure, and thus a larger compressibility, i.e. a smaller B. This interpretation links Ap(↑) and B(↑) along the [A]Ni(C2N3)3 series, providing a heuristic understanding of the observed pressure response within this series (Fig. ). Given that Ap is very sensitive to chemical functionalisation of the piperidine backbone, we here show that chemical changes of A + are highly effective for manipulating B.