Instead of running it in real time as a plug-in, after tracking the vocals go back and do an 'edit pass' thru the vocal track. Select the section of vocals you want to work on, open up AT from the audiosuite menu, tweak it however you want using AT, and then hit process at the bottom of the plug-in window. Then you can move onto the next section of vocals you want to work on and do the same thing until the end. It's more work but it'll let free up some processing power. I only use AT in the graphical mode, so I'm not familiar how well this works in "auto" mode....but it would be worth giving a try at least. d