Okay, this obviously would require rework of the capship interface to implement this.
- Cargo load/unload between docked ships.
Overstuffing most likely will be fixed, so load/unload between docked ships will be important.
This load/unload can work similar to stations. When you dock at the capship, this tab should be accessible right away, maybe under Tactical, but not when you take control of the capship itself. To make this work the Hangar have to be reworked too in a way, that you can actually select the docked ships, similar to stations, instead of launching with it right away.
Obviously selecting a ship in Hangar would cause to leave your capship, but still staying docked with the selected ship
Its basically putting some parts of the station interface to capships.

- Changing addons on docked ships, while docked in a capship
This would be nice too, even now. Like instead of carrying a separate ships, you simply could carry the addons, and change addons when needed (this would be useful for quick addon change while PvP, or while having to carry repair equipment, like carrying one avataur when going to the unknown system, with additional repair modules, intead of an additional centaur).

i suggested that but you gave more detail.