I experimented a bit with the following .ini settings.
Here are the screenshots to show the changes (or non changes):
This first screenshot iswith default ini settings. Look at the shadow of the tree.
This is the same tree/shadow with the iCanopyShadowScale set to 2048 instead of 512. The shadow is blurred. I noticed no FPS gain (51FPS in both solutions). But the shadow definitely looks different. It might be more usful in bigger forests...
This is the same tree/shadow with the same ini setting changed, but this time lowered to 128. The shadow is much crisper. But personally I think it looks kinda weird. I like the 256 setting best.
Not a revolutionnary setting but people with lower configs might want to try augmenting that value. You still get the shadow, it still looks ok. You jsut do nt get each leaf's shadow...
These 2 screenshots look exactly the same as the default settings, so I couldn't figure what they are for. Maybe you guys will notice something I did not.
Setting changed: CanopyShadowGrassMult=8.0000 (default was 1.000)
Setting changed: bDrawShadows=1 (default was 0)
To sum up, if you want your shadows to look crisper, just lower the value for iCanopyShadowScale (default =512). If you want it more blurry, add to the value. I would advise adding only values that are multiple of 8s, since the default was 512. You might, on lower configurations and in lushious forests, gain performance by blurring the shadows.