But then you get people stuck half-in and half-out of the zone.
Zonebricks use triggers, which I believe detect by worldbox instead of a single .position field. Meaning a player can barely be in the zone and it would kill them.
I'm not too familiar with the hack, but I can't think of a way people could get in a safe zone in time to live without already being in it at the time the platforms fall.
Also the fact that when the server isn't processing their movements they're immune to zones anyway. They regularly get into the killer water in Speedkart.
It still keeps track of their positions, though.
And zones (triggers) and water are completely different things.
Keep in mind right now I'm not trying to say the hack doesn't matter, if it may seem that way; I'm just throwing out ideas for solutions.