... What I'd much rather see than the endless proliferation of mini-maxed (often ineptly) designs just to bulk out yet another book is how different races fill the basic niches of free trader, yacht, liner etc.
... Of course there would be standardised hulls, drives, staterooms etc as in a universe of thousands of planets and trillions of sophonts the demand for ships is enormous and the industrial capacity matches that demand. Plus standardisation allows modules to be easily replaced and ships to remain in service for centuries and even millennia.
An ineptly min-maxed design is an intentionally flawed design to show corporate politics and the whims of foolish, but powerful people still prevail.
Several recent book HAVE shown ships from several races. Is your gripe more along the lines of my favorite was left out? It also runs counter to your gripe about wanting to have fewer designs, because in game stagnation and boredom.
And there it is again, wider standardization means more ship types.
You can't have modular Elite Dangerous hulls, restricted to 40 designs, if you only allow the few types shown in CT. But you can do that IYTU.
If you like the idea of standardized modules: make some; give them the standardized discount; and then make some ships that can use them.
And as Fluffy Bunny Feet said, YES. There should be millions of designs from five thousand years across all of Charted Space... and a bunch of them SHOULD suck.
In Amarillo Design Bureau's SFB Romulan fleet, the new ships were made modular, so that after a couple of weeks in a shipyard, they emerged with a different profile. Except the modules were not compatible with other ship classes, with the exception of a few failed prototypes.