I think the peppers and frost vases making antidote could just be a side effect of the enzyme being able to spread everywhere again, so eventually it ends up in the plants, but it would still be better if you had to use a peeper or something as an antidote ingredient if that's the case.
Bigger and spookier map, and more space so we can have a cyclops again or something like it. Also I want more purpose to the arctic spires.
Jellyshroom cave has lots of magnetite and other good stuff.