Yes. Thank you.
If the only requirement is to show proof of vaccination, you simply put the officers back on the front line and get them to ask people to show proof of vaccination. You don't need the application to do that.
Again, on the idea that this app is easy to complete, I can tell you, and you can ask anyone working on the front line, that it is working all day helping people complete that app. It is not to say that it is a free app to use when you know what roaming fees are in a foreign country, not to mention that at many of our ports of entry we don't have Wi-Fi for them to complete it.
The app is a big problem.