Yeah, have to 100% agree on using Lambda. The reality is the sensors are reading lambda anyways.. then just multiplying by whatever factor you tell it is right for whatever fuel you're running. You could put E85 in the thing and if you don't touch the AFR factor in the gauge it's still going to say 14.7:1 when you're @ stoich for that fuel
I have no feel for AFR #'s so I'm always converting them to lambda anyways at this point