For each object that is casting a bad shadow, you could try setting it (in the transform section) to stationary instead of static. This causes shadows to be computed for that object dynamically if my understanding is correct, and produces a far better result. I have experienced the same issue, and asked the same question. https://answers.unrealengine.com/questions/847700/how-do-i-fix-bad-lighting-on-small-objects.html