Just wanted to say, that this is a great mod, I have been thoroughly enjoying it, and it's definitively something I've been waiting a long time for.
That said, there are still a few minor issues with it. Specifically, I'm talking about least effort, which is something others have touched on. I appreciate the idea behind best effort, but, as others have mentioned, what ends up happening is you get consecutive orders for deliveries of minute quantities of items. Every train that doesn't have something better to do gets roped in, and even some trains that do have better things to do. On top of that, they end up clogging your rail infrastructure, because you've now got 10 trains which are waiting to each pick up 50 iron plates. One train would've sufficed, but instead there are 10, plus the other 10 that came before, and those that will come after. To an extent it is possible to get around this, by using a decider combinator that only outputs once there is a certain amount of items stored in the output station chests, but even this isn't perfect. In the time it takes a train to get there and take the items, the system will have time to call other trains to pick up marginal amounts of items.
You are doubtlessly aware of all this, so I'm not going to post all this without offering a solution. Perhaps you can think of a better solution, perhaps there's some reason why my solution won't work, but since I haven't seen it mentioned, here it is.
When using least effort, have a minimum time between deliveries for each item/resource. This could be a config-able option, with a default of say, 5 minutes. Essentially once the system sends out a delivery using least effort, it will create a 'timer' for that resource, and won't create a delivery for that resource based on least effort until the timer has expired (5 minutes in my example). This will give time for the output station(s) to buffer up a sizeable amount of items - possibly enough for least effort to not have to be used, and should overall be more efficient in train usage. Better to have one half full train than 50 1/100th full trains.
Like I said, perhaps this isn't feasible or you have another solution in mind. You would be right to say that I could turn least effort off. But, I like the idea behind least effort, and would like to see it improved. You might also say that if your inputs match your outputs, none of this should be a problem. I would counter that, this is an unsound argument. To expect to always have inputs matching your outputs is a flawed expectation in a game like factorio where you are constantly trying to expand, and where trying to increase your red circuit output (for example - this happened to me) might mean having to increase several different production chains, which can take a lot of time. Time during which your trains are now running amock, delivering 20 red circuits at a time.
Still, love the mod, great work, I appreciate what you've done.
