Closing httpd mod_proxy connection with a RST after timeout

Issue

• Currently, httpd always closes a proxy connection with a FIN after encountering a timeout waiting for the backend's response. Is there a way to have this closed with a RST instead?
• The backend does not always reply back with its own FIN. This results in the socket persisting in our firewall, leading to potential issues when that port number is later reused and denied by the firewall, which thinks it is still in use.