When allocating, we have the "Override Consignments Delivery Run" option on several different places within the application.
One is on the Bulk Allocation screen, which has a default controlled from the Organisation Settings.
Another is when you "Move" a Consignment (this always defaults to unchecked).
And a third is if you "Edit" a Run Sheet (this always defaults to checked, and I'm not sure what effect it has).
Suggest connecting the default for these back to a common org setting, they could feed off the existing Bulk Allocation Setting with an update to the wording around what the setting does.