Potentially unappreciated input below ....
You know what you are doing but why would you run a carbon rim on a bike packing rig, especially a generic type carbon rim which I assume you are looking at?
Wouldn't the ability to bash it back into shape if you get damage in a remote area be a bonus with an alloy rim? It's not like a bike packing rig is going to be sprightly, even with light rims.