Big World Maps Terrain: How far i can go with UE4?

For my game UDK3 editor limits was the biggest limitation.
UE4 is as UDK3 or has a bigger editor limits?

I’m making a 200 x 200 km game
or 1500km x 1500km

How Big can be a map?
Are you working on an true infinite editor? Large map big world vast terrain

I wish this as improvement in the core of DirectX 12 and not via software outside the gpu.

Thanks for the work done!

Links to similar questions:
It is possible create a map with more than 400km? ??? Which is the largest maximum size of land?

Okay so this means the scene moves instead of the player, am a bit confused.

Also, if that is true for that method, is level streaming possible for open worlds to be technically infinite?

So the UDK 10x10x10 Km limit can be exceeded?

And physics always works fine?

Searching in the ue4 f.a.q.
“…create and customize large, open worlds. Landscape paves the way for terrains that are orders of magnitude larger than what have been previously possible thanks to its powerful LOD system and efficient memory use. Quickly and easily create outdoor worlds allow for any type of game!”