Nothing in this game costs anything, only takes more time to build.
Which really doesn't matter (only if we are at war with people who keep launching attacks and building new ships).
But what I wanted to say is that it's impossible to make such a ship lower than TL10, and it would take hours to build, and to really make it rescue ships could be a hassle. Don't forget that wormholes are taking ages to load.
It's insteresting however, in some situations. Like if the ship's hold is full of goods & money, or if you bought it, and it's stranded (can't respawn), then you'll need to rescue it.
But again, why would you do all that to rescue a ship that only require 2 clicks to build/easy to manually repair?
It would only require a quick repair to systems and around 100 units of hydrogen.
So no, I don't think there's a need for it, but it would be cool to see one of these.
Also, a TL7 ship takes one hour to build.
About 15x15, I don't remember how big is my ship, so I can't answer that.
Of course TL7+ ships are bigger than that.
...for the sake of a less effective design that is aesthetically pleasing and that has an easy-to-understand layout.
Well, then we are talking about different things. As I said, ship design is individual. You do it for aesthetics ATM, I'm doing it for combat.
A faster ship can be really helpful if you want to get out of enemy weapon bay range. A TL7 can do 17.000 damage in 1 shot depending on how the bay was designed.