Is it ok to do my full worldmap on the persistent level and then fragment it for level streaming in some way?

[anonymous_user_128d48a2]

Should be, you can export your terrains from Unreal to Grayscale and .fbx (I think)

Greyscale you could use a program called TileMage Image Splitter
then import in into l3dt and convert it to the correct format.

Someone more knowledgeable could give some other options