I read the same thing about them, you just never know. Copper treatments plus a small confined space, less than ideal for him. Only thing I can think of would be to take some sand from your display, water from your display, and sacrifice a rock to go into QT tank #2. Could also seed some biomedia tonight as well, (in your DT) it would basically be insta-cycled by tomorrow and ready to go. But that’s a lot of potentially unnecessary effort. Is there anything you could add to that tank to break it up a little so it’s not so wide open? Fish like shade/ places to hide and maybe that’s all the wrasse needs.