OpenBSD httpd.conf conditionals

Note: this question is about the built-in OpenBSD http server named httpd and its configuration. It does not apply to any other web servers.

Is it possible to make runtime conditional configurations of the new OpenBSD http server httpd? A naïve example would be

server "myserver.com" {
  if $REMOTE_ADDR == "127.0.0.1" block drop
}

to disallow local access.

Another, perhaps more relevant and illuminating, example would be in the case I am implementing an interface to a remote service that runs from a specific place, then I would benefit from something like

remote_service1_ip = "192.168.0.1"
server "myserver.com" {
  location "/remote_service1_api/" {
    if $REMOTE_ADDR != $remote_service1_ip block drop
  }
}

If this is possible, what is the correct way of doing it?

More generally – there are a number of predefined macros specified in the man-page of OpenBSD-httpd.conf as described in the block:

$DOCUMENT_URI
    The request path.
$QUERY_STRING
    The optional query string of the request.
$REMOTE_ADDR
    The IP address of the connected client.
$REMOTE_PORT
    The TCP source port of the connected client.
$REMOTE_USER
    The remote user for HTTP authentication.
$REQUEST_URI
    The request path and optional query string.
$SERVER_ADDR
    The configured IP address of the server.
$SERVER_PORT
    The configured TCP server port of the server.
$SERVER_NAME
    The name of the server.
%n
    The capture index n of a string that was captured by the enclosing location match option.

and I would like to know how to use them. Using $REMOTE_ADDR in a redirection context seems rather silly to me, and I guess there should be something else to use them for, but I can't find or understand any such use case in the documentation.