The way I see it, optimized shaping does matter, it's just that the most basic shape, an elongated box, almost works well enough, just like a barge or raft works. If you want a fast or efficient design, then you need exotic geometry like the series of Enterprises or D7. But, if you care only a little then make a USS Raven, which is just a huge Danube class runabout, which is just a fancy Type 6 shuttle. Even the Holoship isn't a shoe box, it has obliquely pointy leading edges.
At the same time you are completely right, too. There is so much room for exotic shaping which must be just as right and effective as the Federation and Klingon designs, otherwise everything would be flying wedges. So, while blunt shapes don't work well, warp physics might like extremely complex shapes of any sort.
Just saying.
