>Possible to play video on external monitor from iPad Pro via USB-C?'
>This is presuming they had a USB-C capable HD monitor, of course.
That would be an HDMI-capable display, or Apple has it's own 'DisplayPort' capable displays that can be added to that chain...note they go at the end.
From this link https://support.apple.com/en-us/HT209186#displays
"When you connect an external display, it mirrors the iPad Pro built-in display, unless you're using an app that has a "second screen" experience (such as a video app)."
Have you explored the options provided when the iPad is in kiosk/guided access mode...might not be any need for an app.