I've been watching GTC 2020 presentation and noticed the new Spread Function OSL input for emission distribution. This looks very handy.
I've had a look around in C4D Plugin 2020.1.5 and well as SA 2020.1.5 but cannot find it.
Here's screengrab from the presentation
Here's a screengrab from the 2020.1 Features list on the Otoy website.
It looks like it should just be OSL code that could be copied into the OSL texture.