The sinkhole gets a coal when you place it, so placing and mining it over and over again yield infinite coal and therefore iron ore in the very early game.

This is probably an exploit but it seems super fun with recursive blueprints

It's definitely an exploit. Needed it to not use electricity and that's all I could do till .17. It wasnt intended but if it's working for u have fun

["ghost-fuel"] = {
flags = {
"goes-to-main-inventory"
},
fuel_category = "chemical",
fuel_value = "1kW",
icon = "base/graphics/icons/coal.png",
icon_size = 32,
name = "ghost-fuel",
order = "a[ghost-fuel]",
stack_size = 1,
subgroup = "raw-resource",
type = "item"
},

maybe something like this?

Maybe. Overall it's not that big an issue as I'm going to fix it when .17 drops and adds a void energy source

Ok, thanks for the mod!