This is a mod for Factorio that lets you fix a broken research tree with very little code. Just download this mod then unzip this and look at 'research fixes.lua'. It only allows you to change the prerequisites and needed science packs, but that's probably enough. You can make a local edit for your own mod collection, or you could also make a fork of this for your modpack with pre-packaged fixes. Anything goes.

I don't actually have a use for this, but someone else probably will.