Ugh,

> 3. adding "set_real_scheme_from" and "real_scheme_header" directives to the realip module that manipulate the $scheme & $https variables in a similar way to $remote_addr.

Of course, "set_real_scheme_from" is unnecessary, since it'll be the same list of proxies as "set_real_ip_from".

Revise as:

3. adding a "real_scheme_header" directive to the realip module that manipulate the $scheme & $https variables in a similar way to $remote_addr.