Wow, this looks fantastic! No one ever mentions that the Apple displays integrate with the brightness controls on macs. This can be a major quality-of-life feature if you work during the day and night and don't want to keep changing brightness on multiple monitors every day.
However, I have non-Apple displays as well. Just tried https://lunar.fyi/ via usbc and it worked great so far!
I see a lot of questions on the internet on “how do I control monitor brightness on macOS?” and a lot of “just use Control+Brightness Up/Down” answers from people not realizing that only Apple vendored monitors support that.
And that’s only possible because Apple implements a proprietary USB protocol inside their monitors for changing brightness so they have smooth transitions and be sure it works every time.
I’m pretty sure they’ll never touch DDC/CI for that, and rightfully so as it has very spotty support, especially with these new Thunderbolt hubs/adapters and smart monitors.
However, I have non-Apple displays as well. Just tried https://lunar.fyi/ via usbc and it worked great so far!