Are the system requirements much heavier than the base game?
And... is it free? Seems like a massive amount of work. I think I'll give it a try.
Probably, Nehrim was very heavy on the GPU and processor since they liked to turn up the object density a lot and in certain scenes there could be a lot of NPCs running around, wouldn't surprise me if Enderal followed in the same footsteps.
And yes. It is a mod. Therefore it's free.