This study would have been virtually impossible without the open source OpenFF data and software infrastructure, which enabled rapid prototyping and rapid iteration through multiple fitting experiments. Additionally, the benchmarking infrastructure allowed us to identify systematic errors, and we plan to employ this going forward to help us fix critical problems even before releasing force fields. All of the datasets and infrastructure used here are openly and freely available under permissive licenses. We hope that this work and the open procedures described in this paper facilitate further force field development cycles both within OpenFF and in the broader community. We anticipate considerable room for future fixed-charge force fields of the form employed here, but many other avenues for further work are open as well; for example, off-site charges are likely important in certain key chemical environments and should be explored and polarizable force fields are also of considerable interest. We hope OpenFF infrastructure and datasets can provide a foundation for further exploration in these areas as well.