i am reading the patch notes and aquifers are only under y 31 for the time being so it is not a intended feature currently
So your saying that the entire ocean is aquifer under y49
Which of its true then that is personally pretty dumb
the command works for me even at y=300
i did use the search function but i did not see any.
from my knowledge(which is little) is removing infested stone from below grimstone level or adding infested grimstone that generate in grimstone levels.