It's not about confirmation on pasting multiple lines, it's about confirmation on pasting lines that contain a linechange at the end (hex: 0D 0A)
"multiple lines" implies a line break, which is why what I'm talking about is the same as what you are talking about, the feature is there: a confirmation message when pasting content with line break.
Edit: after re-reading your post, I'm not even sure about what you are asking for because you are saying you are asked on both cases for confirmation (cases being pasting "one line of text" and "one line of text\n" where the \n means a newline, while using the single line feature for the editboxes). Being asked for confirmation when there's a line break is what you are looking for, isn't it?
