These work arounds may work but they do create many extra steps, each of which open up opportunities for human error like entering a customers information wrong in a draft order (happens all the time). Shopify should absolutely listen to this problem and add a simple “create additional label” button which allows seller to make new labels with new shipping details like box size and weight while automatically filling in the buyers other info. This isn’t a question of there being a work around or not, this is an incredibly useful tool that would be easy enough for Shopify to add and it should. I used to use a similar feature on Shippo all the time until they eliminated it. Now I have to manually enter peoples information and screw around with layers of complication for absolutely no reason other than I have to work around a poorly designed system. It has the ability, it just doesn’t care. This is not a rare problem, it is a stupidly easy thing for Shopify to make that would solve a very common and unnecessarily complicated problem.
I need to use this feature right now, twice, for two different orders because the shipping warehouse accidentally fulfilled all the items when one of those items (which must ship as 2 separate packages because of size and weight) when they did not have all the bits to ship at that warehouse. These small features are what make the sellers on your platform more efficient, which makes their businesses run better, which brings in more sales, which directly benefits Shopify. Its not just a kindness, it literally helps your bottom line and you have people on staff already that could know this out in a couple hours. I love Shopify, I hate inefficiency and unnecessary complication.
TLDR: Just make it happen Shopify, we would all benefit. Build the best product you can especially when its so simple to make better.