Why would somebody touch up a book with glue and CT if not, for the sole reason, of restoring it to a better condition ? This may be some quote Borock and CGC used at the beginning to justify the logic behind allowing it in a Blue Label but I don't see it holding up today. Let's just say the book had a non color breaking crease, holding the book to 9.4. Any improvement with CT/Glue would not be enough to overcome that crease. However, in today's environment, the crease can be pressed out. If so, now the book will improve with the CT/Glue.
I am giving you the explanation that has been given to me by several CGC graders (and I have owned several books with these notations, hence my interest).
Unless their policy has changed, I would assume there are plenty.