OK so I'm not clear if this is proposing that once the pool is exhausted mobs continue giving SP. I'd assume not since then obviously the best leves would continue to be the best leves, unless you set the pool for every leve to give the highest amount of SP attainable on any leve under any conditions.

So unless I'm missing something, there is now no real incentive to push the stars higher, or form a large group, as the SP pool would just diminish faster, but for no greater reward.

Please correct me if I'm wrong, not sure I've fully understood.