I don't use any.
Although one thing about the game that is really bugging me is getting repair drones intoy stations.
It doesn't seem to work as it's supposed to.
In theory all you need to do is set the station to buy drones in the logical overview, give it the cash to buy them and bingo, they should at some point appear.
Everything I've googled said this is all you should need to do.
However, I've done that and nothing...after easily 15+ hours of in game running time.
So Google more, some suggest it might be based on the management skill of the station manager, so I seminar him up to 3 stars, still nothing....
Ok, so try to take matters into my own hands, buy the smart chips and drone parts and energy cells which the station puts out an order for, trade the wares to the station, nothing......
Try to dock a capital ship with repair drones equipped to the station to transfer the drones from ship to station, except that fails as the station doesn't have cargo drones, so I'm back to square one.
Frustratingly, one of my stations did get the drones, but honestly can't remember exactly what I did in what order to achieve this.