Some mobs, I've noticed mostly animals, jump too high when in water.

something about D:globalSwimSpeedMultiplier=1.5

The swim speed modifier is an iffy one. I couldn't find a neat solution, since in the code modifying the swim speed attribute changes all 3 directions at the same time. This feature is mostly added with the request of the commissioner and is a known issue, but it's not something that I know how to easily fix. Try using smaller values and hope for the best, or don't use that feature at all. Sorry :/