Have you tried increasing the shadow map size to 512 or 1024?

I like to use 1024 with two lights having a .35 shadow and one having a .65 shadow. Tends to make the shadows softer and removes some artifacts created when the maps hit low poly areas.

Have you tried using ray traced shadows to see if that improves things?

The Amiga rocked. Loved and miss mine. (I hear Commodore's back but their Amiga's are more PC than Amiga now).