Change tmp directory

[Blackbit]

In case of a hack on our server we would like to change the tmp-Path of each domain to /tmp. This is because we applied noexec to the tmp partition wich should be much more secure than a tmp-Directory. The hacker executed perl in the tmp-Directory of a domain, where we can't deny the execution of scripts. How can we change the path? Is it sufficient enough to link (ln -sf) the directory to the /temp-Partition, or will Plesk overwrite it on every change on the hosting?

Regards,
Blackbit