I like to tow big gas mining stations to gas giants and let tankers pick up the refined fuel from there. If you want to minimize inefficiency, you currently have to use order delays and approximate how long it will take for a fuel harvesting station to extract and refine enough fuel so a tanker can be filled up in its entirety.
What I would love to see would be a “Refuel until full” order. This would make setting up routes for fuel pick up from harvesting stations so much more convenient. Pretty please!
One complication with such an order is how to decide what happens when multiple fleets are using the order on the same target at the same time.
In most cases, I think, you’d want one fleet (perhaps the one that arrived first) to get all the fuel first, until it is full, and only then does the next fleet start to get fuel.
But maybe there are other use cases where you’d prefer the fleets to refuel in parallel.
The convenient thing about stacking “load minerals until full” orders is that the time it takes to perform the order depends on the free cargo space remaining in the fleet, and all the minerals on the colony remain there until an order completes (at which point they are instantly transferred to the fleet).
So when two fleets are stacked with that order, one of them will finish first, and will get all the minerals it can fit. If not then full, it will begin the order again, which will take less time. Meanwhile, the second fleet to finish will likely get comparatively very few minerals (maybe zero, maybe a day or two’s worth of production/packet arrivals). When it restarts the order, it has more capacity remaining than the first fleet, so it will need more time to finish.
The difference between the order completion times of each fleet grows larger with each iteration. So while it does allow some “leakage” to the second fleet, it’s not a very big effect overall.