For testing of the active learning protocols, the chemical space was assembled by combining the pyridyl moiety with 508 R-groups and 100 of the most common linkers from the FEgrow library. A total of 47710 unique molecules were successfully grown into the binding pocket and scored using the gnina CNN scoring function. A further 1656 molecules were assigned a penalty score of pK = 0 as they could not be embedded due to steric clash with the protein. In cases where rare errors occurred, such as a failure to assign force field parameters, the molecules were discarded completely.