ProRes 4444 with alpha channel is huge for anyone doing app demos — you can drop the recording onto any background in Final Cut or DaVinci without the green screen nonsense. I've literally been shelling out to `ffmpeg -vcodec prores_ks -profile:v 4444` after recording with other tools to get this, so having it native is great.
Curious how the per-window capture works with alpha — last time I messed with SCStreamConfiguration it got weird with sheet overlays and the menu bar bleeding into the frame. Did you have to work around that or has Apple cleaned it up in recent SDKs?
Also worth mentioning for anyone wondering why not just use Electron/Tauri for this: ScreenCaptureKit gives you the hardware encoder path directly, so your CPU isn't pegged at 40% during capture like it is with ffmpeg-wrapper approaches. Real difference if you're recording while actually trying to use your machine.
