Setting up shadows for large terrains?

I’m having trouble figuring out how to set up the lighting and shadow quality properties for a scene with a large terrain with trees.

I have two directional lights in the scene with one of them (the sunlight) using soft shadows with high resolution. The terrain object is using pixel lighting with cast shadows on. In the quality settings shadow resolution is set to high, shadow cascades to four and distance to 50.

The shadows look nice on my player object (which is a tank) and other objects, but the shadows from trees and the terrain itself behave strangely. If I drive my tank to an area which is shaded by the terrain itself, the foot of a hill for example, there is a strange ring of light around my tank. Also the shadows from trees are cut off at a short distance from my tank, there is a sort a torus shaped area around the tank in which shadows are visible, instead of a circle like I believe it’s supposed to be. The shadows from trees also flicker in and out depending on where the camera is looking.

In short, is there a way to have objects cast their shadow on the terrain, but have the terrain still use just the lightmap?

50 is a horribly small shadow distance suitable only for very short view range indoor scenarios normally unless your scale is tiny.
Already the fantastic 300 distance for terrains of 2000x2000 is microscopic at the standard view distance of 1000.

and yes you can use lightmap + realtime light. just calc the lightmap and then use pixel light mode

If I set the distance any larger than 50 the shadows on objects turn into strange lines and everything looks like there are window blinds in front of the sun.

Also turning on pixel lighting for the terrain results in the issues I have with the trees and the strange light/shadow auras. Everything would be fine if I could just have the terrain use lightmap but still have other than terrain objects cast shadows on it.

The light is coming from quite a low angle because the scene is set at dusk. Could that cause problems?

Any more advice, anyone? Are there any examples I could look at?

the quite low angle indeed can become a problem especially when the shadow texture space runs out. Though at a shadow distance of 50 it should not be that visible cause most stuff is not realtime shadowed at all (unless you made the terrain tiny, not its normal 2000x2000 size … in that case it could become a precision thing)

the glow auras around shadow casting objects on the other end is “normal”, I don’t know anything to do against that

I tried changing the light angle to a bit higher, but the shadows still flicker and jitter and look absolutely terrible. The terrain is the standard 2000x2000. I tried to switch the terrain back to lightmap lighting, but the trees still cast shadows on my tank which looks weird when there are no shadows on the ground.

Is there really no way to have things cast sharp shadows on the terrain without having the terrain cast shadows on itself/other objects?