From what I can see in RA forum posts people have brought it up on numerous occasions but it gets shot down as being a way people could cheat and RA being designed with online play in mind.

Have any efforts actually been made to enable offline achievements? It would be nice to have for handheld emulators that do not have built in WiFi. Even if it was something that was synced locally and you couldn’t upload it to RA’s website I’d be interested.

Hell I’d even be curious to try out a self hosted solutuon.