IMO the best approach is developer opt-in. - developers render UI to an HDR buffer - developers standardize on a open-source brightness slider in the Menu Bar

IMO the best approach is developer opt-in. - developers render UI to an HDR buffer - developers standardize on a open-source brightness slider in the Menu Bar - or, each app has an individual 'brightness' slider. It's a lot of work and a shame that Apple is making us to do this, but if a handful of apps start to do it then perhaps they'll come to their senses and just let users control their own damn screen brightness.