My suggestion today is to allow the construction of PDC's with stockpiled ship components.
Here's what I was trying to do. I started with a group of relatively small shipyards. All in the 7k to 10k size range. So, its taken me awhile to build up to the SY big enough to build ships with the 25kt Cargo hold needed to ship prefab PDCs.
So, I had a bright idea that at least seemed to make sense. I'd build the components I'd need . . . the size 1 missile launchers, the mags, the missile fire controls, the sensors etc that I would need to build a rudimentary defense post. Then, I'd ship them over to the planet I wanted to protect. Then the construction factories and the construction brigade over there would dig the hole in the ground, pour the concrete, build the basic crew quarters etc, install the ship components, and I'd have a PDC over there. Seemed to make a bit of sense.
Tried it, and of course it didn't work. I found a threat on the Academy pages that said components are added to a ship when its added to the shipyard. Since the PDC doesn't go through the shipyard, the stockpile of ship components is left untouched and the game is telling me that its going to take 3 years to build the PDC.
So, changing the PDC construction code to have it use any stockpiled components would seem to be a nice add.
Actually, I'd also make a second suggestion to change the way ship components and the shipyards work. If a shipyard knows a component is under construction, they could probably plan their work such that when the component arrived they could plug it in. So, I don't know how difficult it is in the code, but it would be nice if a ship under construction could accept ship components that come from industry after the construction is begun and still have that speed up the completion of the ship.
But my main suggestion is to have the PDC construction code at least recognize that components are available and use them. Doesn't seem to be much harder than spotting them, raising the completion pct of the PDC in the factories, and erasing the stockpiled components. If you cancel the PDC completely later, the components are just gone.