The ACO parameter "ProxyTrust" is used in the combination with the ACO parameter "ProxyAgent" of the Reverse Proxy Server.
1. The behavior is depending on the value of "ProxyAgent"
case 1: ProxyAgent=yes
Yes. All authorization events are skipped on the back-end server. Only the authorization events from the Reverse Proxy server are logged in the smaccess.log file.
case 2: ProxyAgent=no
No. Authorization is done on the back-end server again and the events are logged in the smaccess.log file.
2. No. It isn't recommended.
"ProxyTrust=yes" means the back-end Web Agent trusts the authorization results of the front-end Web Agent. This setting shouldn't be used without protecting with the front-end Reverse Proxy Server with the Web Agent.