In some business models, multiple shipments / orders are required to be combined in a single sales invoice lines. It is especially essential in Online Travel Reservations business B2B Invoicing. There may be hundreds, even thousands, of order or shipment lines to be invoiced combined in several lines only.

A similar feature on Purchasing side is already announced by BC wave 1 (2026) update.

Why not for Sales Invoices?

In my view, it is a big gap between Business requirements and BC features.