Need confirmation of behaviour of using :PlusItem

I’m trying to Count the number of Contacts that a User selects from a list. This works to an extent but I also want to include in the Count any email address that a User has entered into an Input Field.
I’m doing this by employing a button that, when it’s clicked, creates a Custom State which is a list of all the Selected Contacts’ email addresses :PlusItem [InputName’s Value].
The problem I have is that the :PlusItem adds 1 to the Count even when the Input is Empty. This means that if the User only chooses Contacts that are in their address book, my count is out by 1. I’ve tested this with a text box on the screen with a condition that displays the text “Empty” only when the Input box is empty.
My Questions are;

  1. Will using the :PlusItem option always add an entry that gets included in a Count?
  2. If so, dhould I create a second Event to create the list of Contacts but “Only When” the Input Box is empty and then subtract 1 from the resulting Count?

:plus item adds an item to a list. If you have (something):plus item (something else) and (something) is empty, then the final list will be just (something else).

Try checking ‘this input cannot be empty’. I think Input’s value is ‘empty’ but that empty state is being added as a text to the list. I didn’t actually know you can add empty texts to a list but if I had to guess then that’s what’s happening here.