I don’t see anybody pretending to know anything other than stating their experiences with maintenance and the reputation of the tuner. I did a LOT of reading in many forums before picking Livernois. They’re known for being reputable and I’m confident they have done testing and data logging and know what the A/F ratio will be. Most people don’t have wide band, high precision stand alone air fuel measuring equipment to independently confirm parameters(yes, I know the EB 3.5 uses wide band natively) You just have to trust you’ve picked a competent tuner to start with. From the reading I’ve done, there are a bunch of tuners who are less than competent. Plus, Livernois had the technical ability to design their own tuner, not just use an off the shelf product like SCT that 99% of the other guys use. I know enough about electronics design to know that this couldn’t have been an easy task, and you need a pretty intimate understanding of electronics, coding, and the ECU to actually design the interface yourself.
The only thing they need help with is website design because it sucks. Lol