Examining the inaccuracies of the SMARTS hierarchy offered a few insights as to why certain labels could not be resolved and resulted in an accuracy below 100%. We found two aspects that complicated the results and limited the accuracy. First, we found that some molecules were seemingly assigned incorrect types. This prevented any SMARTS-based methods from determining the difference between the two GAFF types. Second, we note that the aromaticity model between BESMARTS (here, the MDL model from RDKit) and GAFF were differ-ent, and so GAFF types that indicated aromaticity were mapped to chemical environment SMARTS that were not considered aromatic by the MDL model. This introduced pressure on the split search since it had to find other SMARTS primitives that represented the same information as the aromaticity primitive. However, the best accuracy of 99.8% is still quite accurate, and there were very few cases in the SMARTS hierarchies which exhibited these issues. Importantly, most molecules that we fit to individually resulted in 100% accurate hierarchies.