I think I am stuck “stupidly”. Lets say I have a L-System and as a leaf input I have a sphere SOP and I want to have my spheres to have an attribute with a random value. I ve been trying several approaches and none worked. There is the LeafParam A but I dont get it to work neither. I was expecting this to work like a copy/stamp.
If anyone knows, help will be appreciated.

It looks like a bug to me. I've logged it.