I’m not even concerned about the visuals to be honest. If it was simply a single-line field the same as it currently is, where the text overflows off the end of the text box that’s fine by me. I’d only be using the input field for “paste” > “enter” when trying to do multiple tasks, assuming the input field can correctly identify separate tasks based on new line or break tags.
Trying to split into a multi-line field could get messy if you try and create 10+ “tasks” at once. It also kinda defeats the purpose and you might as well just enter them separately.
The only real use case for this that I can think of is for quickly pasting content in. It would be nice to just be able to “Select all” > “Copy” > “Paste” > “Enter” to get things in. Bonus points if it can strip common bullet point formatting (eg. “-”) and numbering from the start of each task.
Could you automatically convert new-line or break tags into a delimiter of some sort (eg “;”) when it’s pasted into the field? This could make it easy to spot and allow the user to move sideways through the text to edit if required.