I have an iPad Air 3 (2019) and it’s still 4:3 ratio. In contrast, my older iPhone 6s+ has perfect crisp mirroring. This is using the AV lightning connector with HDMI
The issue is that the app doesn’t support true mirroring capabilities. Many other apps have had this feature for years. Consider YouTube, Google Slides, and I believe Real Racing 3.
In YouTube, for example, when you mirror over the adapter and HDMI, it sends a full res, full screen video to the monitor while having a control panel on the iPad. You can even close the iPad and it still runs the video.
Zwift should
Allow Mirroring at full 16:9 aspect ratio over HDMI
Allow it to continue to run while the iPad is locked or closed.
This would open up the viewing options and make the iOS experience more enjoyable.
Right now running Zwift on iPad and output to TV without full screen is actually “true mirroring”. Other apps that can run on the iPad while outputting a different image to the TV is not mirroring but displaying a differenet image. Many streaming apps can do this because the video streams from a different source. For example Netflix and Youtube can output full screen if it’s streaming (while displaying a remote control on the iPad), but will only do mirroring if the movie was downloaded to the iPad.
But since Real Racing 3 can do it then it’s certainly possible for Zwift to do this. It would be really, really cool if the iPad has a Zwift companion type of screen while outputting full screen to the TV.