I know that this is not the only thread on this, but I think that way too much time is spent on starbase construction. I'd argue there's more time being spent on starbases than on planet management and ship construction combined. It gets to the point where it detracts from the enjoyability of the game.
What is needed is a simpler system. Otherwise, late game in large maps ends up being bogged down on starbase management.
I propose something simple:
First constructor: Builds a starbase
From there, starbases are like planets - you just build whatever modules you want and can ask a planet to supplement its construction if you want to hurry or pay a fee to get the module instantly. That should be much easier and much less time consuming. Just queue up what modules you want.
Also, I think that starbase defenses need a buff overall - perhaps with the option of building super power starbase defenses that can resist a decent sized fleet (kind of like Sins Starbases) - at a price of course.