RADIUS support for ssh access.
There are a lot of things which you can only do on a shell. Either with ssh to the box or with the serial console. One example might be tcpdump /cc commands/ grep.
However, logon does only work with loginuser and or as root. Having multiple admins, you never know who does what. And this is a nightmare for auditing or troubleshooting reasons.
Therefore, I would recommend to enable RADIUS authentication (or other authentication) for ssh and console access.
I really would prefer a behaviour like most other network devices:
Logon to the box based on RADIUS authentication for WebAdmin, ssh and console. And if the authentication server is not reachable, fallback to local user database.