There are parameters that are carefully adjusted to maximize the quality of the shadow at the small resolutions that MakeUp uses, and that give you its speed and quality. (For example, the default shadow is only 512x512px.)

These settings prevent "flicker" of shadows, herbal quality, acne of distant shadows, etc.

Providing that capacity would lose the benefits of those adjustments. To alleviate this lack there are "far" versions of the shadows.

This functionality will not be added, for design reasons.

However, anyone is free to fork it. That's what it's here for.