i have a fast doubt and i couldn't find it in faq

so basicly a have a 10k by 10k generated world and i wanted to use dh on it, that means i dont need to use internal server to generate lods right? i mean, when i use internal server it downloads the whole chunk when i just needed the lod right?
another thing, when i use features it takes too long to generate, could it be c2me?