ReplayKit Live Streaming Custom Video Feed?

Is it possible to feed ReplayKit with custom live stream data, e.g. a cvPixelBuffer created from a Metal Texture, and stream that to youtube? My use case is to give the broadcaster hidden UI manipulation controls that the stream audience cannot see. (Think of a DJ. No one gets to see all the DAW controls on the DJ's laptop and doesn't need to because that's not part of the experience.)

If it's possible, might anyone be able to help figure out the correct way to implement this? From what I can tell, ReplayKit doesn't let you send custom data, in which case, what else can be done?

ReplayKit Live Streaming Custom Video Feed?
 
 
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