I wonder if the system notes new value is the free form text field type which would mean it would truncate at a string length of 300

@JohnnyC I think you are correct. I exported the saved search results and the count of characters from that field is 303 (3 of which being the periods). What a bummer.

So Long text, rich text, and text area fields in theory all have the same problem, I can see why NS might have done this. So if you want to know the exact change it appears we're on our own to come up with a solution.