With transition attributes you can influence the solver to prioritize nearby visits. However the solver takes into account all parameters you use to influence the solution on top of route conditions including traffic. Sometimes the best solution will include some overlaps if those result in better final routes.

Can you please give it a go to transition attributes as defined in the article below and provide feedback on the result?

https://developers.google.com/maps/documentation/route-optimization/prioritize-nearby-visits

There's also a Google Maps Discord server with multiple channels in case you want to join! https://discord.gg/p68Pem7PzR

Best regards, Caio