Nearly got killed a few times by the server lag too myself.
I did get killed by way of mob lag one time, but it was my fault for AFKng in the open and I did get my stuff back.
I've noticed several areas which are glitched caves in that theres a huge area which is missing the stone down to bedrock and even the soil sometimes, they don't always have flowing liquids though. Theres a really big one to the northeast by the hot springs which I was at yesterday, lots of flowing liquid there which could be contributing, however, it's pretty far from most peoples render distance. Might be just in range of Bla and Blotz though.