Hi Felipe,
have you checked with any abaper, i think they might come up with a way of customization where you will get a pop up from choosing from multiple routes based on whatever criteria you want(like customer etc)
they can maintain a Ztable for this and fetch the route from that.
Because in lon run, manually entering the route everytime is going to be cumbersome and is defintly prone to error and mistakes.
I will suggest to go for a customization which will allow you to choose from multiple routes.
Regards,
Aayush Jain
SAP SD Consultant