Ok, i looked into your code.
As I said, one key can’t have two values. That’s one thing you are doing on your definition. Maybe concatenate them and send it that way.
Another one is that you don’t have to repeat the key by list length. Take a look at the below definition.
Sungbok Extend Parameter.gh (44.9 KB)
Just to understand it better, what are you trying to do? Can you explain your use case a bit?