My previous experience with slime chunks made me quite excited to find that I'd serendipitously placed my Botania setup in a Skyblock map right over a slime chunk. I figured a few Narslimmus + a few Mana Spreaders = mana goldmine. Carefully worked my way down to Y=38, and started a floor there, fencing off along the chunk borders. Placed my first Narslimmus so that its range was entirely within the chunk, and linked it to the spreader in the ceiling. Wandered off to get the materials together for a couple more (I was thinking four total, set three blocks in from the corners), expecting to see at least a little profit while I was away. So far, nothing. Any advice? The floor is made of Baobab planks, in case I've somehow stumbled on a weird form of spawn prevention.
EDIT: Never mind. In this, as many things, patience was needed.