What would be useful is if the "formation editor" allowed for the distance 5,000 km as the minium interval. So I can tell a ship be 5,000 @ 30° from the protected ship as opposed to the current minimum interval of 10,000 km.
I would also suggest changing "Final Defensive Fire" to be at 10,000 km for a ship shooting at inbound missiles targeting itself but at whatever the the range to the ship being hit by missiles this 5 second turn for the other ships in the formation. So a ship 20,000 km away will engage the missile hitting its consort but at a hit probability calculated by the range to the consort (in this case 20,000 km). Based on what I saw this may be the way that Final Defensive Fire is working but not having to pack all your ships into a sphere 10,000 km across with the primary target in the centre would make formations easier to use.