Allow <script> tags in document templates e.g. packing slip
Allowing scripts in packing slips would enable vastly more powerful customization.
You could reference external data from a server e.g. serial numbers.
You could implement complex customs declarations and make the packing slip match. For example, if you have an item you don’t want to make a declaration for, such as an add-on or surcharge, it currently still shows up in packing slips, which customs officers may delay approval over.
You could do arithmetic and so much more for custom tabulation.