There seems to be an undocumented change with how nukes work in this mod. Is there a way to disable this feature?

I've since learned that this is a Vulcanus thing. Seems like Nauvis is counting as Vulcanus with this mod pack, which makes using nukes pretty costly (they leave permanent lava lakes behind).

Upon further research it seems that because this mod allows both Ammoniacal ocean and Lava to exist on Nauvis, the crater is actually a mix of both. I've made a mod that removes this (in general, so it works for regular Vulcanus/Aquilo too).

https://mods.factorio.com/mod/no-crater

I now have so many code-related questions and nobody to ask them to. Does the atomic bomb decide what tiles it should create based solely on what tiles were there initially? Does the mod genuinely use a surface other than the default one for Nauvis? Has anyone ever even fired a nuke on Aquilo?

I now have so many code-related questions and nobody to ask them to. Does the atomic bomb decide what tiles it should create based solely on what tiles were there initially? Does the mod genuinely use a surface other than the default one for Nauvis? Has anyone ever even fired a nuke on Aquilo?

The fun thing about Factorio is that it's largely human-readable in LUA, at least for anything mod-able. You can see the effects in this file:
\steamapps\common\Factorio\data\space-age\prototypes\entity\explosions.lua

As far as I can tell, it doesn't check for tiles, no. The effect trigger is based on pressure (which this mod must mess with to allow all planet-specific effects/buildings/tiles to exist on Nauvis). The new tiles are placed using an effect type "set-tile" and while there is a "tile_collision_mask" set, I don't pretend to understand how that particular aspect works.

As for why the mod allows it? I think the second-to-last section of code in data-updates.lua basically removes all surface conditions.

I would be curious how many people are aware that there's a nuke effect on Aquilo and on Space Platforms (yes, there's a hidden 3rd one that I didn't remove because it's not permanent like the other two). I suspect Vulcanus is the most known as there's little reason to use nukes in those other two places.