Holding backorders from pick releasing

Couple of questions: In 12.1.3;

1. I am trying to find a way to prevent backorders from releasing to whse for certain items. Excluding backorders in release rule is not an option for us. Tried logging 'error' severity shipping exceptions but no luck as they still release to whse with the exception.

2. Is there standard functionality to do sales order line split automatically based on defined split criteria during order line entry (not on partial shipment)?

Any inputs appreciated..

Thanks!

Yogesh