AVPlayerItemLegibleOutput contains Core Media attributes

When using AVPlayerItemLegibleOutput to obtain a sequence of subtitles from a video stream the results are returned as NSAttributedStrings through AVPlayerItemLegibleOutputPushDelegate method:

func legibleOutput(
    _: AVPlayerItemLegibleOutput,
    didOutputAttributedStrings strings: [NSAttributedString],
    nativeSampleBuffers _: [Any],
    forItemTime itemTime: CMTime
)

Inspecting the string's attributes I see that rather than NSAttributedString.Key values such as NSAttributedString.Key.font, NSAttributedString.Key.foregroundColor we have Core Media attributes such as CMFontFamilyName and CMForegroundColorARGB.

As these attributes reflect the user's device accessibility settings for subtitles and closed-captions they should not be ignored. Unfortunately UILabel cannot render them.

So my question is what is the correct approach to rendering these strings (when automatic player caption rendering isn't suitable)?