There is a method of manually removing , temp and %temp% folders, that we have used during some stubborn removals in conjunction with the Norton Removal Tool.
We have also removed certain plug-n-play driver files.
I do not recall ever suggesting to remove the Prefetch (there are mixed reviews on that - the same as there are on running a Registry cleaner).
In the past, I remember troubleshooting with a Symantec Rep and PREFETCH was most definitely cleared. At that point, did not notice any adverse reactions. From time to time, whilst performing general maintenance, I will clear this folder. Maybe timing has something to do with it? In times cleared more frequently, maybe I have noticed (on my laptop) wireless connectivity issues and/or certain icons not appearing in systray? Probably because those executables have been temporarily cleared. A system restart seems to remedy any quirkiness. In speaking to a representative from Malwarebytes', he apprised me that clearing %temp%, TEMP, PREFETCH, and cookies is routine maintenance and would not impact MBAM's performance.