Splitting tax and freight when splitting orders

[UPP]

Hello,  we need a way to, when splitting an order, be able to split the tax and freight as well.  When more than one item is on an order, if we need to split them we need to be able to provide a packing slip that has the accurate tax amount for that item.  It is currently lumping any freight and tax on one shipment. 

There are several improvements that need to be made for splitting orders.  Ability to apply a new order number, ability to cancel one of the orders, (in cases where we are splitting because one item is unavailable, and in cases where a customer cancels only part of their order).  I'm not sure why these things slipped through the cracks.