Allow ships to be built into naval admin commands.
Instead of being built to a target fleet, new ships could have the option to be built to a naval admin command. Once built, they would be formed into a single-ship fleet with the ship name (the same way detaching a single ship from an existing fleet currently names the new fleet) which is placed under that admin command.
This would help manage some of the micromanagement involved with managing shipbuilding for large empires, since building into a Shipyard Fleet still requires clicking to detach and scrolling + dragging the detached ship to the proper place in the hierarchy, which can be tedious for ships intended to operate alone (e.g., survey ships, tankers, stabilization ships, industrial ships which will be immediately redeployed, etc.)
I would suggest that admin commands be color-coded as green in the shipyard drop-down menu to make it easier to parse the list of fleets and commands.