This mod works with the research cost being automatically adjusted to use rocket, space, and utility science (however the cycle time is 15 seconds which might be low), but the artillery shell uses 30 U-235 making it significantly cheaper than a regular atomic bomb, would it be possible to make the recipe for SE the same as in SA?

Hello! Appreciate the interest and suggestion. As far as parity between SA and SE, absolutely, can do.

Do let me know if you have any questions or additional suggestions.

Hello again! Just wanted to share that with the release of version 0.3.0, the recipe should default the U-235 to 100 when either SA or SE are present.

Additionally, I went ahead and made several aspects of the nuclear artillery shell item, recipe, technology freely configurable via startup settings (attached a screenshot to the mod-portal page)

Do let me know if you have any questions, concerns, or any further suggestions - happy nuking!