Charge-carrier mobility descriptor Concerning the charge-carrier mobility descriptor, 67% of the COFs have effective masses of both electron and hole below ten times the electron rest mass (m e ). The threshold is chosen because most of the effective masses reported for COFs with high conductivity in the literature are below this value. At a much tighter threshold of 1 m e , still, 35% remain, among which only 6% are 3D COFs. Figure shows a distribution of the effective masses of both electron and hole for the evaluated CURATED COFs. Out of the structures with effective masses of either electron or hole higher than 100 m e , 18% are 3D COFs. high effective masses uniquely contain glutarimide (with dicarboximide group). In Figure , a pattern can be seen for β-ketoenamine-linked COFs with TIBT, its presence occurring mostly on COFs with low effective masses and appropriate IP/EA values for aligning with HER. Statistical analysis with bootstrapped effect sizes shows a significant difference between the means of effective masses of COFs with and without β-ketoenamine linkage with TIBT (lowering of 2 units in the log scale for both electron and hole Figures ). Indeed, β-ketoenamine-linked COFs usually display good photocatalytic properties for HER, with increased stability with respect to their imine counterparts. However, the same COFs, except for a few, present higher values of the computed charge recombination descriptor (Figure ). It has been suggested that introducing donor-acceptor units to COFs with this linkage can enhance their photocatalytic activity by stabilizing excited charge transfer processes. Concerning the before-mentioned MC-COF-TPs series with low charge recombination descriptors, their uniformly distributed N and S heteroatoms are also expected to enhance charge-carrier mobility. Such observation is corroborated by the computed m* for both electron and hole for MC-COF-TPs, that range between 5e-10 to 13 m e , with the exception of m* h for MC-COF-TP-E 1 2 E 2 . In summary, when designing COFs to enhance chargecarrier mobility, choosing 2D dimensionality and β-ketoenamine linkage with TIBT could be advantageous.