Sure it is. It's probably best to install priiloader along with it, though. That way, you can bypass the system menu and enter bootmii directly.
Granted, if the wrong IOS is accidentally removed, you still can't access bootmii. But it still offers better protection than not having a backup ready in the first place (eg. if you're having a banner brick and missing the IOS the homebrew channel uses, you can still restore that backup you made).