Some gathered notes that help me solved this problem (thanks everyone!):
When using Stationary or Movable Lights on a movable mesh (not static) the shadow visibility of that movable mesh is dependent upon the size of the mesh and its distance from the camera.
Command Line Values to Tweak:
r.Shadow.FadeResolution - controls how big the light has to be on the screen before it starts to fade out.
- Default Value: 64
- Can lower this value to keep shadows from fading out at further distances
r.Shadow.MinResolution - controls how big the light has to be on the screen before it finishes fading out, at which point it no longer has cost.
- Default Value: 32
- Lower values seem to increase shadow visibility.
r.Shadow.TexelsPerPixel - Causes a higher resolution to be assigned and then it should fade out less aggressively
- Default Value: 1.27324
- Can increase this value to improve shadow rendering visibility & quality
r.Shadow.RadiusThreshold
- Default Value: 0.03
- A lower value of 0.02 or 0.01 greatly increases shadow visibility at far camera distances (seems to have the most impact of all the console commands).
Useful Link: https://docs.unrealengine.com/latest/INT/Engine/Rendering/Scalability/ScalabilityReference/index.html