No, it’s not possible to monitor the user’s activity in real time after reserving the pump.
Please keep in mind, that the use of the device outside of the car while fueling is forbidden. So theoretically, the user would have to either cancel the session being still in the car or go back to the car and cancel it (if the nozzle wasn’t picked up till that time). So, with regards to this, hiding the Cancel button is not necessary. In the edge case, if the user would take his device with him anyway and would try to cancel the flow once it was already started, he would get an error (cancel not possible).
