BTW, I discovered that at the Brightline checkin gate actually gets the latest update from the central computer if needed, when you scan the boarding pass. So even a very last minute seat change will be detected and if different from what is on the boarding pass one is asked to go to a kiosk and get an updated boarding pass, so that the latest seat assignment appears correctly on it. It is important to have the right seat info on the boarding pass, since a human has to read it and match it with the numbers on the platform and on doors and seats in order to actually find ones seat. Until we have eprfected the update to the brain patch to be able to feed it directly to ones brain, we are stuck with printed paper or Smartphone App documents.
Many (most?) airlines already offer the option that you don't need a printed boarding pass but can scan either a stored pdf, or use an app to pass the gates.
The advantage of an app is that they can update information in real time, so strictly speaking there is no need to send you back to a kiosk.
If the app is GPS enabled they can even use it to check whether or not you have boarded the train, and no-show bookings can be released for the benefit of passengers boarding at subsequent stations.