what is the point of extraction systems because not sure the extraction commodities have much use in game.
Lots of advantages, I think:
- extraction is a lot easier to build than refinery - asteroid bases have it intrinsically, and there are quite a range of surface and orbital constructs which provide it as influence (which are mostly also cheaper to build than hubs, which take a fair amount of commodities and a T2 point)
- it produces gold, silver and palladium which are excellent trade products (and very useful for trade missions), and imports lots of things from the likely places to sell those metals for setting up a good return trip
- it produces a lot of bulk ores which you can convert into metals using a Refinery contact at a favourable cost rate without having to mine your own - or sell to a Refinery economy to push it into Boom and increase its production
Its outputs aren't directly useful for feeding future colonisation projects, but it has plenty of wider uses.
I have only seen posts about incorrect positions. Not unlimited slots being added.
It looks like someone has attempted to do so - 74002 and 74125 - but been defeated by the issue tracker.
(It may also be the underlying cause of the "outpost inside a coriolis" bug, if it doesn't actually add a new slot, just fail to note that the existing one is full)