Great mod. Different enough from Long distance delivery drones to keep things interesting. I'm using both.

Not a big deal, but right now I'm using fuel with a stack size of 100 and the drones are going to the refueling mooring when the fuel is half empty, which seems a bit excessive. 200 total fuel and the interrupt is 100. I realize they are slow but the interrupt could trigger at a lower fuel amount. Maybe the interrupt could change depending on the stack size of the fuel.

Thank you! Hope you'll continue to enjoy it

Yeah, I was thinking about it already, because I realized yesterday I had made it a bit more stupid than that. Because you can change the fuel inventory size in the settings, but it only checks if it's missing a single stack. So you if you have 100 fuel slots but only have 99 stacks of fuel, it goes to a Refueler

My current thoughts are to make it check the percentage fuel items left, and as long as it's one item above a configurable limit; it will be considered as having enough fuel. So if the limit is 25% and you have 2 fuel slots, it will refuel only if there's less than or equal to 26 Coal, or 11 Rocket fuel, or 1 Nuclear fuel

Also, fun fact: I didn't know about Long distance delivery drones when I began this mod, and it covers the exact use-case I needed. But I'm in too deep now :P

That sounds good. If its going by the total of all the fuel, I think 20% would be fine.

Alright, I ended up making it a bit simpler. In 1.5.1 the refuel interrupt is triggered by dropping to a percentage fuel level that defaults to 20%
And yes, it's now calculated by totalling all fuel, not just counting stacks