Just something related to extended water physics: It works a bit strange and is generally slow, too slow.
I will try to fix that, if i understand, how it should be looking. At first - strange part. Describe, what you find strange. Second - slow part. This may be caused by slow server TPS, also water work faster, than lava, because i want to give player time to run away.
Remember, that this feature is completely server-side related and can easily be turned off (without nessesary config sync). If this thing is too annoying, just ask invultri about that (to set enableExtendedLiquidPhysics=false). Of course, it needed server to be restarted, sorry about that.
Hm... digging in code, i find out, that you couldn't block liquid movement by placing a block on its way. This?