In OpenSSH root cannot login. In TinySSH, which also implements the ntru exchange, root is always allowed. I don't know what the behavior is in Dropbear, but

In OpenSSH root cannot login. In TinySSH, which also implements the ntru exchange, root is always allowed. I don't know what the behavior is in Dropbear, but the point is that OpenSSH is not the only implementation. TinySSH would also enable you to quiet the warning on RHEL 7 or other legacy platforms.