If there's nothing to attack when rolling the 6 (5+ for 4 Mind), the hero can move the dice but once something is in range, the hero will lose it. From that space is where the range starts. A hero would need to move carefully when sensing that smell is getting too much for them. Remember they can still smell at distance, it just when they get too close, when too excited. Adding this to the mod opens up more control to use it effectively.
If used for character it would need High Mind. If as a curse, this is bad news for the barbarian. He's going to need a Talisman to not have to put him down. Which for those who use this to give the Wizard an extra spell set, a good way to nerf him for a few quests. UK Talismin gives 2M not 1.