Hehe It's funny how some players LOVE this feature, and others really dont care for it. I personally LOVE spending 20 minutes and perfecting a design, but to each their own 
We are working on a list of feature to get in for the next few updaates, and I think this feature will make it in (the "copy design" feature), though you can save your designs under a different name, which kinda has the same effect (though you still can't upgrade form Core designs).
Also, look for the ship design library, coming soon to www.galciv2.com
where other players will post their creations, and you can pull from these and make ship building a less time-consuming process.