This suggestion has been thrown about and has been kept on the sidelines for way too long.
An indicator which shows the leechiness of the card, regardless of it’s type (IO, basic or cloze) could be on-display in the menu bar on the top as the user is reviewing to make the user take a much stronger initiative to tackle all leech cards as they are forming.
A simple lapse count is not a robust method to identify the leechiness of a card. A review to lapse ratio is a better method but still not robust enough.