I agree with you.
This used to be possible when the feature was first implimented, but there was a bug in the feature where it was calculating and displaying line counts incorrectly. When Khaled correct this, it became no longer possible to block ONLY pastes that would send text to the channel... and NOT pastes that simply fill your editbox.
Ideally, this paste protection should only kick in when text is destined to hit the channel. If the text only fills your editbox or multi-line editbox, the paste protection should not trigger.
Paste protection is meant to prevent accidental and embarassing pastes to a channel. You can find the option under ALT+O > Other > Confirm. (to all readers)
- Raccoon