I think this might have been suggested once as part of another post a long while ago (found after some searching), but I haven't seen anything on it since, unless I'm just not looking hard enough. 
One feature I would like to see is auto-replacement of destroyed ships. For instance, if you have a fleet defined, you can designate a shipyard to automatically build a replacement ship when one in that fleet is destroyed. I tend build fleets with a certain "mixture" of ships that I like to keep; keeping track of which ones get destroyed in order to replenish with the same type after a battle can be a chore. So it would be great if one shipyard could just build replacement ships automatically to maintain that mixture.
Here's how it could work:
1) Define your fleet as usual
2) At any shipyard, link it to that fleet and turn on the "auto replacement" feature
Options:
- You can set minimum levels of available resources before any replacement ships are automatically built, such as 10000 credits and/or 1000 metal
- The replacement ships can either jump to a way point as normally set, or set to join the fleet wherever it is (and follow it around until it does successfully join it)
Thoughts?