I got a service that connects to a third-party SFTP site to pull files. The third-party has a system that when certain users try to connect, it automatically blocks the incoming IP. Someone is doing some connection attempts while using the forbidden user as due to be a legacy system, any user gets to the system as root. Whenever this individual tries the sftp root@remote-site he/she just breaks a couple of applications that rely on the same remote SFTP.
Question Is there any way with SSH to block this outgoing connection for a specific user@site? Match rule is for sshd_config which is basically incoming. Is there an equivalent for ssh client?