Currently playing with Space Exploration, but getting a fusion reactor set up on a new planet is a huge hassle without power first since the only way to move deuterium in a rocket is to use a bunch of hydrogen cylinders, a deuterium centrifuge, and solar panels for power. This needs waiting several minutes for all the reactors to come online then more waiting for the pyrolysers to begin producing hydrogen.

I think either having a recipe to uncraft deuterium micro capsules or being able to store deuterium in the hydrogen cylinders (since its the same element after all, just a different isotope) would be useful!