I don't think this was intentional, but there's no way to get coal on vulcanus anymore except for coal synthesis, which is found on gleba. Given that coal is your only source of oil products (and foundries require lubricant) this not only forces the player to go to gleba first but can easily result in a softlock if they haven't.

I love the mod Idea but having something as vital as oil synthesis locked behind a random military tech on a completely different planet seems like a bit of an oversight.

You actually say in the mod desc that you're relying on coal synth but you don't actually give us coal synth lol

Don't know why that recipe's tied to rocket turrets in the first place that seems like something you should be able to get in multiple ways