I’ve noticed that if you leave a vehicle at a base, it will still lose durability if you leave the direct area. I’d like to be able to keep a vehicle at each bases, and have the mechanics bench protect them all simultaneously, regardless of player position. I had a vehicle at each of my 2 bases with enough resources for 3 days each. When I came back to my first base (after delivering the second vehicle with it’s resources at the second base) I found that the resources were still used, but the vehicle was now at half health, when I made sure to repair it to full before I left.
I suspect that vehicles that are being actively protected should be loaded in game memory, since you’ll have to keep track of the resources anyway.
Also a different poster said that you can mess with people by parking vehicles outside of the base and making the bench service other vehicles, and that seems like a big exploit.