The linbo clients ssh authorized_keys file should be extended with server root's authorized_keys so admin clients can login directly into linbo clients.
With a following ssh config entry
Host <custom_name>
Hostname <lan_hostname_or_ip>
ProxyJump <extern_or_lan_server_address>
User root
Port 2222
you can then passwordless connect to linbo client with
ssh <custom_name>
The linbo clients ssh authorized_keys file should be extended with server root's authorized_keys so admin clients can login directly into linbo clients. With a following ssh config entry
you can then passwordless connect to linbo client with
ssh <custom_name>