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

Hi guys. hope someone can answer my question.
I am learning how to use the unreal engine. im planning to dedicate 10 years to make a really neat mmo.
I have heard that for a big world map it is good to do level streaming. so my question is.

Is it ok to do my full worldmap on the persistent level and then fragment it for level streaming in some way? is the engine advanced enough to let me do this? or am I forced to do it by levels from beginning?
Hope someone can help. many thanks.

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

perfect. at least I know its possible. and there are ways to make it work. thank you so much for your answer. have a nice day