With carriers such as couriersplease, hunterexpress, Auspost eparcel the packing slips are included in the same PDF as the labels meaning they print alternating.

For MyPost Business and Border Express for example the packing slips come in a separate PDF and are not printed after each label.

Requesting that with all carriers when "print packing slips with each label" is enabled the packing slips are in the same PDF as the labels, alternating for each order so it is label - packing slip - label - packing slip.

Shipstation reportedly supports this for all carriers.