Thank you for the expansive mods Brevven, nice to play new stuff with mods like Krastorio.
Question about the green circuits. When building anything with green circuits in them, then engineer will not build them as part of a bigger recipe. We can only build items with circuits in them if we have them prebuilt. So until they are mass produced in the factory the player must manually build all green circuits then build the items that contain them. Is this intended, or a bug that fails to link the green circuit with other recipes?

Yeah this is a tricky one. With the Natural Gas mod, green circuits are made from bakelite, which is made from a fluid (formaldehyde). As such, there is no way to enable handcrafting for bakelite.

You'd have to at least have a few basic chemical plants making bakelite. If you have bakelite, copper plates, tin plates, and lead plates in your inventory (assuming you're using Lead & Tin mods), you can handcraft green circuits. At that point you should be able to handcraft other recipes that require green circuits.

Do you think this is too much annoyance in the burner phase? I know some people play the burner phase by hand-feeding furnaces and handcrafting virtually everything else.

If it is too annoying, I could add a mod option to enable an alternate hand-only green circuit recipe (similar to what Pyanodons does).

I noticed this as well, and so far it has not been a big hindrance--it's a nice bit of complexity like many of your mods add. But I can see how for some playstyles it'd be a big issue.

Two solutions seem most obvious, though they're very different:

1) include an expensive/inefficient green circuit recipe that lacks fluid ingredients (presumably using wood or stone instead of bakelite, as K2/SE do).
This would make it possible to handcraft GCs at any point in the game after they've been unlocked, at a cost.

2) include a cheaper/more efficient green circuit recipe that uses plastic
This would make it possible to handcraft GCs later in the game, and also allow more efficient automated production. I worry, however, that it would render natural gas mostly useless after the early game, except perhaps for hydrogen production. A solution might be to add a recipe for converting nat gas to pet gas, allowing plastic production without dealing with oil byproducts. This would keep it useful at least as an alternative to oil. I can imagine games that wouldn't use oil at all, instead relying only on nat gas for plastic and sulfuric acid, and on coal liquefaction for lubricant and flamethrower fuel.

I've added an optional handcraft-only recipe using wood. It defaults to off, and cannot be used in assemblers (i.e. for automated production chains you must make bakelite, even if you turn this recipe on).

richarnd, I do also like some of your ideas around natural gas, oil, and plastic and will think through them.

For the natural gas to pet gas an interesting idea would to maybe have the pet gas also be an ingredient, similar to coal liquefaction, because I feel like that feature is a little underused in the base game