That would be completely up to the officer. I have always had my ID taken from me for inspection, so I do not believe for a second that they would permit me to hold onto a digital ID while they inspect it. While the technology could permit you to retain control, there would be zero assurance that will actually be the case, and relying on that tech would leave you with no other choice. Once you hand it over, you lose control. What you are reading is slick marketing material published by the manufacturer, not government policy.