At present, there is no way to know which orders have been printed (shipping label printed) and packed, but that still require marketplace notification. The reason why this is valuable information and is important is if something goes wrong with the printing of the labels, you want to be able to select all the orders that you have tried printing the labels for and then you can re-print them. Without clear visibility on which orders are which, you are left guessing and hoping that you have the right ones, based on the sorting order of the SO's and the date.
It is indeed clearly shown in the shipments section, but it crucially does not have the SO's there and neither can you reprint the labels or anything else from that screen. So if this can be implemented for the SO screen too, that would be most helpful.