What’s the optimal toe in for my RT

That's not a published specification. I get what you're trying to accomplish but it doesn't work that way. You'll need a proper alignment machine that can measure wheel position electronically, then, determine the amount of degrees the wheels should be adjusted. Anything you do will be a wild guess and can result in -- at best -- poor tire wear and waste of money there, and at worst steering and handling that is dangerous to you and other drivers. www.repairpal.com/repair-shops