Mark,
I entered a 14,421 character search into SD7-lite and SD7-full and it was still able to match with no problems. I kept going go up and up and up and it keeps doing it without a problem or even slowing down. I assume you’re using NSText searching. I don’t know how large of search that can handle but I’m assuming it is pretty big.
So I’m calling the search good at 14,421 characters. Who would do a 15,000 character search 
Bill