Counter pressure bottling; starting volumes of CO2?

Hey folks...recently had some trouble with bottle conditioning some high ABV beer...deciding to carb this next batch in the tank and use the counter pressure filler to bottle it (i have that medusa rig from Morebeer). Any recommendations for a tank carbonation level; Im assuming there will be some loss in the process. If I want to hit 2.7 in the bottles, should I set the tank to 2.8volsCO2? Any thoughts would be appreciated.