• Texture to Light : Already requested here : https://forum.corona-renderer.com/ Load Textures into Area Lights
• IF Light texture : UV Transform/projection/Border Mode for more control : exemple on this video tutorial for Octane https://youtu.be/3IVCXIuHDeo
• Built in Cinema 4D Target tag (like in the Arnold Light exemple, very handy, personally using this a lot to not say all the time).
• Mixed Sun/sky (all in one) : https://forum.corona-renderer.com/ AIO sun-sky
PS : Roudness can be done by using a circle light (without the transition from rectangle to circle tho, but never used it this way), just showing what is possible and what can be possible.