Player Input component

Probably as stupid question but I can’t seem to figure this out.

How can I detect a “held” button using the new Player Input component?
All I seem to be able to access is the value of button press when using Broadcast Messages.

Is the purpose of Broadcast Messages only simple functionality like that?

How can I detect that a button is being held down?

You can try using Invoke Unity Events.
Then you get a callback context through which you can check for performed and cancelled state. If performed and not cancelled then it is being held.
check this for reference.