What is the recommended setting for large landscapes

I am a programmer, not a level designer, I cant find a good tutorial that explain the recommended settings for large world! the technical guide is written long before world partition, so I believe things are different now

Can anyone with experience who understand the performance cost and drawbacks of components and Grids please explain what is the max limit for them today?
how to calculate it!! or Say I want to make a large map 40-50km with World partition, How big should each section and region size , grid size and how many sections per component and grid size be
considering loading and unloading and the number of threads that will be used

I want to get the common sense, I don’t want to do the extremes because that will be bleeding the PC and slow down the game