Has anyone ever tried installing bitcoind on a 5N?
Yes. And unless you want it just to host a copy of the blockchain, it is a terrible idea. The Drobo NAS’s are completely insecure, and their processor is ridiculously ill-suited for mining.
You can search the forums about people having their 5N broke into once they exposed them to the internet, not to mention the fact that all official apps run as root. Even the internet facing ones.