I completely agree with the Devs on excluding the ship designer feature from this game. It would have no place in a fast-paced RTS.
However, why not have an out-of-game designer application? Players could use the feature to create their own designs (a la GC2) and save them for use in the game itself. I think it could add quite the extra dimension to the core strategy. Perhaps this idea could be realized in a future update?
P.S.
Cheers to the team for making such a great game, I've always had great respect for your involvement with the community and excellent support that you provide post-launch.