If we‘re talking about best values a limit break from ranged/magic dps is a gain in anything but the boss scenario.
The values (taking them from the gamerescape wiki so let me know if they‘re incorrect) are:
2400 potency for the melee lb 1 and 1650 potency for ranged/magic lb 1. So as long as it hits at least 2 enemies its going to be a gain in using the ranged/magic lb 1.