Yikes! You must print money over there...can you send me some 🙂 I won;t say never, but I cannot imagine a scenario when I would argue that needing mixed-mode should provoke spinning up a new instance to isolate those databases that have clients that require it. I am thinking memory management becomes harder and less efficient, licensing costs go up, maintenance costs go up for applying SPs and CUs, and you still have an instance with SQL Logins so what do you get in return? I would love to hear your reasoning behind such a position.