The remainder of the article is structured as follows: First we summarize the architecture of Chemprop. We discuss a selection of Chemprop features, with a focus on features introduced after the initial release of Chemprop. We then conclude the main body of the article, and provide details on the data and software, which we have open-sourced includ- ing all scripts to allow for full reproducibility. Alongside the main body of this article, we provide Supporting Information that contains: further model design details; descriptions of the data acquisition, preprocessing, and splitting of all datasets used in benchmarking; and the results of Chemprop benchmarks on a variety of datasets showcasing its performance on both simple and advanced prediction tasks.