Hi Donsk. Install the Aventon app on your mobile phone. You can pair the phone and the bike display using bluetooth and then modify the bike to a Class 3 bike (28mph top PAS boost/20 mph top throttle only speed) via the app.
You will get much less range per charge than if you set it to Class 2. In Class 2 mode with moderate constant pedaling over mixed hilly and flat terrain I can go about 40 miles using just 15-20% of the battery charge. Setting the bike to Class 3, the same route with the same physical effort takes a bit less time but eats up about 60% of the battery.
It depends on what you want (for commuting where time is of the essence and you don't want to be too sweaty at your destination, Class 3 may be the way to go, but for long recreational tours, in Class 2 mode you can trade a little bit of speed, add some time on the trip and vastly extend your range per charge.
On the "real world" range table for the Aventon they use a 180# rider on the 75# Aventure over a mix of 20% hilly/80% flat terrain with the bike set up as a Class 3. Set to Class 2, figure you double the range per charge shown.