There are a variety of comments from Wube developers on the Space Age discord around the inclusion of Space Age assets in mods that do not require the Space Age executable.
The general sentiment of these comments summarizes to:
- Inclusion of Space Age assets in mods that have a hard requirement on the Space Age executable is fine.
- Inclusion of Space Age assets in mods that do not have that hard requirement is not fine, even if the use of those assets in-game would have a prototype/runtime check for the Space Age executable.
The primary pain point with restricting even the inclusion of sprite assets in mods that have an optional dependency on Space Age is the need to create separate mods that include supplemental code files and the kit-bashed or otherwise Space Age derived assets to satisfy the restriction, while still supporting a mod that targets both vanilla and Space Age.
For a real world example, Space Age introduces another tier of belts which includes a new belt sprite sheet to support higher belt speeds. My mod Prismatic Belts would naturally want to include a sprite sheet derived from that Space Age asset to add a third tintable belt.
Under a conservative understanding of the current unclarified restrictions, I would need to create an entirely separate mod, say, Prismatic Belts: Space Age, whose only purpose is to 1) have a hard restricton on the Space Age executable, and 2) to have the derived sprite sheet. The main mod would then have an optional dependency on that mod and make those sprites available only under that circumstance.
Which would require a player who uses Prismatic Belts to a) know about this restriction, and b) go find and download the additional mod.
It would be significantly simpler if that restriction was only logical (main mod has all assets and a code check on the Space Age executable) and not so strict as to require an entirely separate mod.
This is only one example. I work alongside the mod teams that support Bob's and Angel's mods, and there is a concern that this constraint is going to require us to create effectively two mods for every single mod just to properly restrict the Space Age textures (and maintain our discrete domains).