Changing the line width in a multi line chart

[E1cid]

In order to make code readable and usable it is necessary to surround your code with three backticks (also known as a left quote or backquote ```)

``` 
   code goes here 
```

You can edit and correct your post by clicking the pencil icon.

See this post for more details - How to share code or flow json

As to your issue, try using the ui_control object from the post marked as the solution.