Automatically redirect Tor traffic to onion (Hopefully efficiently as the if processing isn't intensive)

crontab

##Get New Exit Node list ever 6 Hours
57 */6 * * * `curl https://check.torproject.org/cgi-bin/TorBulkExitList.py\?ip\=<yourip> | awk '{print $0" TOREX;"}' > /etc/nginx/includes/torexit.ips && service nginx restart`

nginx.conf

##Create a geo region for Tor Exits
geo $torexit {
    default        NOEXIT;
    include        includes/torexit.ips;
}

site.conf

##Check on every request if Tor Exit, potentially inefficient, but the geolookup is quicker than a long list of ifs. 
 if ($torexit = TOREX) {
        rewrite ^ https://xxxxxxxxxxxxxxxxxx.onion$request_uri? permanent;
}

Thanks @CJFWeatherhead, I appreciate it. It's a good solution.

So in a way, before the alt-svc header this concept was unique and then the TBB-team implemented another client side idea to solve the same problem?