Yeah - ray-traced sun shadows are definitely problematic with distant terrain and nanite at the moment.
My current preference is for VSM sun shadows with distance field shadows enabled for far away, non-nanite objects, and MegaLights for local lights. We’ll see how things go once MegaLight ms supports directional lights.
I don’t understand why HW RT shadows disables Distance Field Shadows though. Would be nice if they could take over for distant, culled geometry.
My editor always “crashes” when it’s closed too.