Does anyone have any direct experience with Pwnage tool enabling multi-tasking on 4.1? are there settings that can toggle multi-tasking on a jailbroken 3G? Can a 3G realistically multitask?

My GF has my old 3G running jailbroken and unlocked at 3.1.2

I'm putting together a custom 4.1 firmware for her and I'm wondering if I should enable the new 4.x features.