Why not add another default sort to the Shipping Label format - sort by Destination (Inland, EU and non-EU)? This would help ensure that all customs labels can be printed rather than using a full sheet of 4 x 6 labels to print one customs label.

At the moment, I have to manually think about the order in which I enter labels onto the system and/or print them off so that I only print off the non-EU labels first