After using rats as a way to transfer items in ATM 6, I can say that their pathfinding over a long distance is quite "below expectation", but I won't hassle about the pathfinding, as we all know, it is a tragedy to code and make it work. So I'll suggest a new feature to fix this instead.

So there's the patrol staff, That I think used to register different patrol positions for guard rats only. Can you make it compatible to rats in other commands as well?
So for transfer rats, they can be registered with different positions that will carefully maneuver them over rough terrains and reach the destination.
Finally, there should be an option in the Cheese's staff rat's menu that once click will automatically delete all of the resignated positions.