Route properties include cost, volume, and structural complexity. The cost of a route is the sum of the molecule and reaction costs calculated using the Route-CostScorer function in AiZynthFinder, following the cost measurement by Badowski et al. . The volume is the number of intermediates that need to be synthesized in a route. The structural complexity is measured as the total SCSscore value of these intermediates along the route. Volume measures the number of items involved in the synthesis process, whereas complexity evaluates the overall synthesis complexity of these items.