Niagara: Processing load in huge scale effect production (100m to several kilometers) and how to optimize it

Working Environment
UnrealEngine 5.1
Windows 10

I would like to ask you the following questions regarding the creation of a huge scale effect using Niagara.
I would like to ask the following questions.

・Load problem when generating particles from a skeletal mesh of life-size of 100m in total length.
Is there any way to reduce the load from the vertex spacing & number of vertices as of now?
Can the effect load be optimized for a massive skeletal mesh, rather than just the amount of generation?

・Is there any difference in load when the Velocity value is more than a few thousand or when the value is a few hundred?
If the scale ratio is the same, I would like to know the computation load when there is a difference of 100 times the spatial size.

・Regarding the float (type), the position of the particle now uses double, but is it possible to set a half-float?
If so, please let me know if it is possible to replace it on each module or all at once.
I would like to reduce the size of the decimal point portion when using it in a huge space.

・Does DistanceScale by Scalability function properly at ranges greater than the real 1 km?
Does it support distances up to a radius of tens of kilometres for distances that may be too large?
If I change the ParticlePosition from Vector to Position, which is a double type, will it work fine even over a vast area like mentioned above?

Thank you very much in advance.