Personally, I have rolled back to Horizons until the functionality of Odyssey reaches that level.
There are a lot of good things about the new layout, but if you can't do what used to be very easy then it fails at the first hurdle.
The devs should have to swap parts from one craft to another craft over and over for a day, parts that are not sold at that station, then let them back at the code knowing they have to do the same again in a little while.
You can bet the process would quickly become quite streamlined and intuitive...