I am wondering if the user that posted https://forums.whonix.org/t/how-to-tunnels-connecting-to-a-proxy-before-tor was jumping to trying Connecting to a Proxy before Tor too quickly.
Could you please check if either Connecting to a Proxy before Tor and/or Combining Tunnels with Tor have an appropriate explanation that Configure (Private) (Obfuscated) Tor Bridges might be the more appropriate solution?