I really fall on the side where the Catch
does reduce what you have to resist for feeding damage, but, looking over the inline example in Feeding Dependency, I gotta say there are reasons to go with Tedronai's interpretation.
For example, if you used Inhuman Strength and Inhuman Toughness in the scene, that’s a total of 4 refresh, so you’d be rolling your Discipline to meet or beat a target of 4.
Seeing as Feeding Dependency itself attaches to powers in the same way that the Catch does to Toughness powers and there's no argument over whether it reduces the amount of refresh you resist against, I'd actually think that it works the same way for Toughness. Once again, in the inline example, it didn't use the whole Toughness suite as the refresh total - it
only used your specific powers within it that were used.
I'd say a hit through your Catch means you don't use whatever Toughness power, so really it's reducing the threshold by the total amount of your Toughness powers. However, if you were hit - even once - by an attack that your Toughness power was effective against, then you would have to resist against it's full value.
LIKE I SAID, I personally tend towards the Catch reduces, but it's pretty open to interpretation.