Expert Preference for Temp Directory

I would like to see an expert preference to specify the temporary files directory as using %temp%. The reason is one of preference and security against malware that targets environment variables.

It would be great to have a MFT wipe of the destination when it's finished as well. Once files and folders have been archived/moved, deleting the files unsafe, but following up with a MFT wipe of the filenames/directories would be fast, secure way to go about the process.