I think it would be really useful to have an processing orders tab
I own a printing company and we use the shipping label / Packaging slip as a works order to create the products. Currently we need to ship the item before its even made in order to get the combined shipping label and packaging slip. We do this to save on printing and paper usage and to stop new orders appearing between the printing which would get missed.
If we had an processing orders tab we could mark all orders we are currently creating as processing before they are marked as shipped which would allow them to be removed from the awaiting shipping tab.
It seems as if this is a logical step, other order management systems have this in place and I think it would cater for a lot of companies that operate like we do.