This is a feature I've wanted for a long time. Considering how GalCiv3 has a very elaborate ship designer, I think having a quick and easy way for us to test designs in battle would be a natural feature to compliment it. Although I'm impressed by what some are able/willing to do with the designer, personally I consider using it to be a bit of a chore as it is, and would never consider doing anything fancy with it simply because waiting for ships to become available over the course of a game (or else fussing around with a bunch of console commands) to see how they perform is too low a work/fun ratio for my tastes. But I would definitely use it, and probably enjoy the game more too, in general, if I could step directly into the fireworks, so to speak... i.e. spend a few minutes creating a couple of fleets of my own design (or any I might choose) and then sit back with a beer and pretzels and enjoy the show.