There are several reasons to perform a Forscan PCM update:
Connect a battery maintainer (not just a trickle charger) to keep voltage consistent. Low voltage is the #1 cause of failed flashes.
A PCM update via FORScan represents the ultimate democratization of automotive maintenance. It allows owners to keep their vehicles running on the most refined logic available. However, because it involves the core operating system of the engine, it should only be performed with a steady power supply, a reliable wired connection, and a deep respect for the technical complexity involved.