The current shipment consolidation policy is nice but has 2 problems:
1. it can only consolidate with Open shipments
2. there is no setup for a date range for the shipping date

Typical scenario:
Shipments should be consolidated per address, and customers place multiple orders per day.
10:00 Sales order 1 for customer X is entered
10:30 Release to warehouse
11:00 Picking starts
11:30 Picked goods at PACK location
14:00 Sales order 2 for customer X is entered
15:00 Release to warehouse: now the new sales order 2 should be added to the existing shipment with order 1
15:30 Picking order 2 starts
16:00 Picked goods at PACK location
16:05 Sales order 1 and 2 can be packed on 1 container through the packing station

Ad 1: as long as the existing shipment is not confirmed or packing slip posted it should be possible to add new shipment lines to it. (See my other idea "Store shipment ID on packing slip and invoice")

My preferred solution direction for an automatic process would be:
An extra optional wave template step Consolidate shipments.
When this step is added after the createWork, the newly created work should be moved to an existing shipment according to the shipment consoldation policy.

The restriction is that the shipment ID must be filled on the work header (work break per shipment).