Here's what I would do. Remove Cobb about 1 mile before pulling into the dealership. It will take your car a good 20+ miles before you throw a code for cat issues. When you go ask them if they plan on driving the car. They usually do for oil change. Tell them you expect them to put less than 12 miles on the car (thats what they usually put on mine) and record the mileage with the service advisor. Act like its a big deal and your anal about someone driving your car.
You should be just fine with this strategy. The problem with the BMS O2 simulator is it takes a bit of time to dial in. It may need to be adjusted before the setting is right for your car not to throw a code. That may take you a few days of driving or 100+ miles to play with to get right.