We have been using Shippypro to manage our order shipments for a few months. It is not cheap but makes order shipping much quicker.
It has a CSCart integration built in to import orders automatically and multiple carrier options.
Shippypro has multiple API and webhook options for developers.
It would be great to have the following additional features:
Order tracking number sent back to CSCart from Shippypro
Order status updating in CSCart based on shipping status in Shippypro
Live shipping rates retrieved from the Shippypro API
Shipping profile fields selectable from shipping profile fields in CSCart
I am sure there are other features also possible.
Would any developers be interested in creating an addon for this or any users interested in sharing the development costs for a custom integration.