I can’t speak to the netboot part personally but I’ve had Docker data folders mounted via an NFS share for a while now, and while it worked fine, I’ve just in the last week or so swapped them all back to local storage for performance reasons (typically anything involving a SQLite database), so depending on what services you’re running via Docker, check that your network speeds aren’t going to be a bottleneck for it. (My home network is only 1G for reference so might not be a problem for you).
She has an arc at the end of ARR where she tries to start, but can’t seem to find anything that works for her (although her Carbuncle allegedly continues to remain summoned).