Hey Numbat,
probably misunderstood the question. I’ll pass along a command he suggested that I try previously:
r.Shadow.RadiusThreshold
try various values. I believe 0.03 or so is the default. What this does is stop rendering shadows based on screen size as an optimization.
Alternatively, try increasing “BoundScale” in the mesh properties. It should be using bounds for this but increasing the bounds may have other unwanted side effects like making more objects render.