Instead of a Drop Ship checkbox in the Sales Order, why not let us choose the Vendor instead?
I have multiple suppliers for the some products and depending on the state. To consolidate the SKUs to a single vendor, I have to go to each product and manually check the drop ship before authorizing the sales order. Once the PO is generated, I have to go back to set it to the original vendor.
A workaround would be to create different SKU's for each vendor like 1A, 1B and 1C. But with variations like 1A Blue, 1A Green, 1B Blue, 1B Green, they will become hard to manage.