Screen recording iPad Pro via USB-c and Keynote presenter mode.

Hi,

I am an a university teacher and would like to use my iPad Pro and keynote for remote lectures, these days. My setup for live lectures is the following:

Hardware: iPad Pro, iMac, video camera connected via HDMI to the iMac via Elgato Cam Link 4k

On the iMac, I use OBS to composite the camera input and the slides to a single screen. OBS detects the iPad, that is connected via USB-c to the iMac as a video capture device (similar to how you can record the iPads screen via QuickTime when connected via USB).

Normally, when I capture the iPads screen like this, it is simply a mirror of the of the original screen. (same behavior with QuickTime).

While this works reasonably well, when I connect the iPad directly to a screen, for example using a USB-c to HDMI adapter, some apps provide options to extend to that screen. In particular, Keynote will show a presenter view on the iPad and the actual slides on the external screen.

I would love to have the presenter view, also when streaming my lectures, when recording the slides from the iPad via the USB connection.

In fact, sometimes this works, but usually it does not and I cannot figure out a pattern, when it does and when it does not.

-- I have attached two screenshots of OBS with the exact same settings. In the captured iPad screens, you can see two different play buttons (highlighted) the normal triangle indicates that Keynote does not detect a second screen, and hence, only a mirror of the screen is captured, the boxed triangle indicates that keynote detected a second screen and will use the iPads screen for the presenter mode) --

This unpredictable behavior makes it hard to rely on the presenter mode for live lectures. If I realize 5 minutes before the lecture that my setup is not working it would be super annoying. So for now I just use the normal mode.

Does anybody have an idea, how I could consistently get the presenter view mode working with a direct USB connection to the iMac? (I have used the Cam Link to adapt the iPad to HDMI and then use the HDMI as input for the Cam Link, but that means, I cannot use my good camera for recording myself)