Selective Memory Purge. Blaschke et al. introduced memory-assisted RL to enforce diverse sampling in REINVENT via diversity filters (DFs). During the generative process, the scaffolds of sampled molecules are stored in 'buckets' with pre-defined and limited size. Once a bucket has been fully populated, further sampling of the same scaffold results in zero reward. We incorporate this heuristic in our proposed method called Selective Memory Purge to enforce diversity. At every epoch, the replay buffer is purged of any scaffolds that are penalized by the DF. The effect is that each augmentation round only updates the Agent with scaffolds that still receive reward, preventing the Agent from becoming myopic and leading to sub-optimal convergence.