This looks quite interesting - I'm looking forward to the finished version!

Are you planning on eventually adding recipes for the major planet mods, or do you think that would be too much effort?

Same here, looks like an interesting approach and sounds like a good alternative to modules. I agree with the above about supporting other mods, since that's probably gonna be a major factor for me.

Nice job though! Will be bookmarking this one :)

I don't feel confident adding recipes for mods that I'm not intimately familiar with. It's important to me to keep to the feel of Space Age, using the same kinds of complexity in the same places, and I simply don't have the experience with most planet mods to do that.

I am building the mod to allow for easy expansion, though, and will be including an API for modders to integrate other planets before full release.

That's a good way to handle it by having the API for other mods to incorporate support themselves. I think that's probably the better option, as they can decide how they wanna balance their recipes around it.