I am using this plugin on my servers. It work ok on low rate servers but on my x1000 it doesn't.  We know it depending on server fps so I capped my fps at 50, set smelt I wanted,  it was ok but checked all today and my smelt is a lot slower than shuld be, my server fps still capped at 50 and smelt is about 20 times slower than day before, nothing in config or on server has changed. 

Set limit to something even higher, preferably to use instant smelt instead.