See pictures. Bigger iceberg structures reach all the way to the ocean floor in an unnatural looking way, instead of floating.

I noticed in the previous snapshot (though didn't have time to report) that a lot of magma blocks were spawning under icebergs in the (deep) frozen oceans and wondered if that was adressed in the latest snapshot, only to find that most bigger icebergs extend as a straight vertical block all the way to the ocean floor now. It solves the magma cube issue, but I doubt this was intentional.