It's possible! ChannelAdvisor now allows via it's API the ability to update line items as shipped instead of the whole order (as ShipStation currently does). Through this mysterious magic of API, they can also send the Shipping Cost, Shipping Tax Cost, and Insurance Cost to ChannelAdvisor. Just image what you could do with all that data! Oh the reports you could run.
I bet you're saying to yourself "Wow, that sounds wonderful. How can I help make this happen?"...
All you need to do is upvote this post so that ShipStation sees the err of their deprecated API ways.