How to share 'back facing' camera app at same time Eye Tracking app needs 'front facing' camera?

While using my xmas present of a new iPhone and iOS 18.2, I figured I'd try the Eye Tracker app. I've been working with clients successfully using Tobii and other existing eye trackers. In my limited tests, Apple has room for improvement.

My main issue is with the camera app which cannot be used at the same time while using the Eye Tracker app. I get an error popup from Apple:

Camera is use by another app

The image below is from my app showing the popup message "Camera in use by another app", but the same error occurs on the installed camera app. This error is from Apple, not my app.

It seems when an app uses the camera, it takes over both the front and back facing cameras. Thus another app, especially Eye Tracking, cannot use just the front facing camera at the same time.

That limits use of Eye Tracking, in particular one cannot take pictures or click any buttons on an app that uses the camera.

Anyone know of a way for an app to not take over both front and back cameras at the same time? Thus the Eye Tracker could use the front camera while the camera uses the back camera.