BlzGetLocalUnitZ

Parameters
whichUnit unit
async
This function is asynchronous. The values it returns are not guaranteed to be the same for each player. If you attempt to use it in an synchronous manner it may cause a desync.
comment

Get a specific unit’s Z coordinate (altitude) (Cartesian System), Z is desync prone, this version might cause desyncs, but (unconfirmed) should be faster, hence why both BlzGetUnitZ and BlzGetLocalUnitZ exist (In case that you are doing a campaign, or something single player, you might decide to use this one instead of BlzGetUnitZ).

note

Terrain height is not synced between clients in multiplayer

patch

1.29

return type
real
Source code
native BlzGetLocalUnitZ                            takes unit whichUnit returns real   
Source
unit.j
wc3modding.com
BlzGetLocalUnitZ