Whenever a cartridge is sort of new and there is a lot of hype still going around, I take all claims with a grain of salt and run my own tests (and math models).
When you have done this type of thing enough, you tend to realize there will be variation in barrels that is "normal" and also you will have the experience to know when something might be wrong or heading for pressure.
Always take it slow and run your own work-ups when in sketchy territory like the latest greatest cartridges. Your first outings are all about caution and safety margin against pressure. It takes many years before the dust settles on fresh designs and the learning curve is full of noise and liars on the internet.
Be careful and safety first cause your mothers are not giving warranties on those fingers or eyeballs.