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This is a classic algorithm design question: to cache or not to cache?

The game does have a list of all the entities in the game, some of which are ghosts, some of which are in range of roboports. The gane has a performant way to filter this list based on many criteria.

The game does *not* maintain a separate cached list of all the ghosts in range of each particular roboport network that have a matching force and no construction robot assigned. Without that, it cannot provide a count of them either. (That is what I would expect from a roboport ghost request output.) Maintaining such a cache in a consistent state would be a lot of overhead. It would need to update (using area searches) every time a ghost was created, upgraded, destroyed, revived, or changed force. Also whenever any roboport is built, upgraded, destroyed, change force, lost power, or regained power.

The devs decided that caching such a dynamic list would not be worth it, and that it is better to do a partial search each tick with the latest state of the roboport networks, etc.

The core problem always seems to come back to roboports having weird polygonistic and overlapping areas. There is nothing to be done about that.

So I see a few potential ways to go about this:
1. Do nothing
2. Have all roboports on the same surface report all ghosts on the same surface, disregarding their own area completely.
3. Have some other entity report all ghosts on the same surface, for example radars.
4. Or do the full implementation where each roboport reports the missing items in their vicinity.

2. and 3. are absolutely worth considering in my opinion, because they allow a functionality that has been missing in the game completely so far.
They are a bit of a paradigm shift in their own right and would still require some non-trivial amount eventhandling, dealing with edgecases and optimization.

Let's look at Aquilo for one second:
The whole planets challenge clearly and unapologetically is designed around having to bring everything there, no exceptions. The perfectly optimized way to tackle this challenge would be as follows:
- Go into a different creative safe with the same seed
- Design everything you need
- Take stock of every piece of equipment
- Go back to your actual safe. Load exactly those items on a ship, drop everything, built it, done.

But I hope most people don't play like that when they first get to a new planet.
A much more reasonable approach is to bring some finished equipment and some raw materials. Ideally you leave some of both on your ship, in case you brought too much. Sending stuff back up is expensive after all. With that in mind you can continue building and either setup the 5th mall of this playthrough or craft every missing item by hand.

What I felt I realized immediately is that this cannot be the intended way to play on Aquilo.
There must be some way to request just the equipment you need from a mall in space. Because if you do that, you do not even need a mall on every planet. A mall-ship that goes around where it is needed or where you are actively working should be perfectly reasonable.

But turns out there is no way to achieve this. I don't know if this is intended, but currently you need a mall (or some sort of automall) on every surface and stockpile enough resources to be able to craft everything that might come up and keep stock of every single item that might be useful (if you don't want to constantly handcraft, which can also not be the intended way to play large parts of this game)

The cost of building large independent facilities (including a mall) in space is already so high, due to cost of space platform foundations and how slowly they are built. So it can't really be an intended nerf to a space-based playstyle either. The DLC is called Space Age, but it actively prohibits me from a playstyle that is focused around that thing in it's name (not even mentioning that it took 2 years for platform-to-platform logistics and the state they are in).


What I am trying to say with this is that, if you want to take a space based playstyle serious, one that does not revolve around this on every planet: Except, that the terrain has a different color underneath (sorry Nilaus). I think you should consider giving players the option to do it differently. And this is unfortunately why I keep talking about these ghosts. They are not intrinsically interesting to me.

But besides all that, it would be helpful for all sorts of other interesting contraptions, I'm sure.