I’m not sure what the intended behaviour is, but if I create a lit material by just connecting a texture of an image to the material color with the cull mode inverted I can then use that material for the skybox. But my Sun/Directional Light is not visible (the light is and the shadow casting, I just can’t see the white disk representation of the light). If I change the material blend mode to Multiply, the light shines through the test sphere in the material preview, but the skybox disappears in the scene.
However, if I use the same material on a simple cube in the scene then look out from the cube it works as expected and I can see the sun disk through the sky material.
Any thoughts on creating skyboxes with a dynamic sun would be appreciated. As would any ideas for blending between two skyboxes to produce a day-night transition.