hi there,
as far as I remember, Unreal 4 landscape Z-Scale 100% = 512 units.
So for a terrain with max. 4096m, you would have to set the Z-scale in UE to 800 (8x512=4096) to get the height of the landscape right.
At least this was my workflow, going from WorldMachine to Unreal Engine 4.22
Now, as I use Gaea and UE 4.26.1 - does this "math" still hold up?
Looks like there is some difference, when calculating the right height-scale in UE.
I got a 4033x4033 heightmap imported.
The Gaea settings look like this:

So the terrain max height (Gaea) is 2250m - 100% Z-scale in UE means 512m or units (if this hasn“t changed)
Z-scale in UE has to be 2250 divided by 512 = 4.39.
Instead of Z-scale 100, this should be 100x4.39= 439 if I am not mistaken...
But at this scale, the terrain is way too flat - roughly eyeballing, the scale for Z in UE needs to be around 850
or something like this - to fit the proportions from Gaea viewport.
Is there a way to exactly calculate, how the Z-scale value in UE has to be set?
Cheers!