It is all extremely hacky. Because HDR allows us to encode brightnesses that virtually no consumer displays can display. And so deciding how to display those

It is all extremely hacky. Because HDR allows us to encode brightnesses that virtually no consumer displays can display. And so deciding how to display those on any given display, on a given OS, in a given app, is making whatever "hacky" and totally non-standardized tradeoffs the display+OS+app decide to make. And they're all different. It's a complete mess. I'm strongly of the opinion that HDR made a fundamental mistake in trying to design for "ideal" hardware that nobody has, and then leaving "degraded" operation to be implementation-specific. It's a complete design failure that playing HDR content on different apps/devices results in output that is often too dark and often has a telltale green tint. It's ironic that in practice, something meant to enable higher brightness and greater color accuracy has resulted in darker images and color that varies from slightly wrong to totally wrong.