
It's worse than many punishments and you even have to pay for it. If having heavy fireballs counts as that, so should this.
I like to use the Cauldron on Transmuters since they can get a really high amount of potions, and it works nicely on Tinkers too thanks to their numerous scrolls, so lugging around an RBS or bought Platemail is less problematic.
While we're at it there are 2 things that could boost the usefulness of NC. First, the boost should apply to both refills on Thiefs (so the secondary effect is half as strong as the primary). Second, when poisoned/manabuned the potion boost should apply before these effects are removed with health/mana potions.
It's sad you can't use the Avatar's Codex and NC together. Would make for a fun Thief combo.