Yeah, typo. I was using RGBA16F, not BGRA16F. I tried not setting colorspace, Xcode shows the values all look good: wantsExtended is true, pixelFormat is RGBA16F, colorspace is sRGB linear extended, and colors are clipped. Ignoring current headroom seems like a violation of the contract, and shouldn't be necessary? It's moot since reference mode returns 10, and I'm still clipping. I watched the iOS EDR and even the Mac EDR WWDC videos, but I'm not sure what I could be doing wrong.